Substrate and Fertilization Introduction

by Robert Paul Hudson
from Robert's web site in Salem Oregon: Aquabotanic.com
Aquarticles


Plants need a balance of macronutrients, (those they use the most of), and minor or trace nutrients, (which they use to a lesser degree).

Macronutrients:
Nutrients used by plants in relatively large amounts.
They are nitrogen (N), phosphorus (P), sulfur (S), calcium (Ca), magnesium (Mg) and potassium (K).

Micronutrients:
Nutrients used by plants in small amounts.
They are iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), molybdenum (Mo), cobalt (Co), and boron (B).

The Substrate is the growing medium that the plants are rooted in. It is important to add a source of these nutrients to the substrate, particularly in a new aquarium that has no mulm or fish waste settled in it yet.

It is also advisable to use a medium such as porous gravel that will provide a good CEC and not compact together. CEC (Cation Exchange Capacity) is the ability of the medium to absorb cation ions, (minerals from fertilizers) and hold them making them accessible to the plants when the plants need them. Sand and coated gravel do not provide a good CEC. Good CEC mediums include porous gravel, clay litter, and clay soils.

Macronutrients include nitrogen, oxygen, CO2, potassium, phosphorus, calcium. Minor elements include iron, boron, zinc, manganese, and other trace minerals. Iron is an important element for many plants and is often added to the substrate with other minerals.

Laterite is a sediment soil that is formed in nature by decaying rocks which are high in iron and aluminum. There are a few aquarium products made of laterite, such as Duplarit, and First Layer. Other sources of iron are soils, clay litter, red pottery clay, and sphagnum peat.

Various substrate methods
- Layered substrate with "sub" soil (soil low in organics), sphagnum peat, gravel, and trace element mix.
- Pottery clay balls enhanced with trace elements, or commercial additives made for the aquarium
- Clay gravel
- Granular laterite, sphagnum peat, and gravel. My mix of choice.

Fail-safe beginner substrates:
Commercial products, laterite, clay gravel, clay based additives made for the aquarium

NPK What are those three numbers?
Nitrogen supplied by the fish, phosphates by the water supply and uneaten food, and potassium to a lesser degree in the water supply. NPK fertilizers should only be added if you have low or unreadable levels already. RO, distilled, and some bottled spring water will be low in NPK and mineral elements. Most tap water will have sufficient levels of P. Even some aquarium products contain NPK. An NPK fertilizer high in potassium, but low or 0 in nitrate and phosphate has the least affect on algae. Check the numbers. Single digits are low, double digits are high. In a heavily planted tank with fast growing plants, and a small number of fish, it is possible to have consistent 0 readings of nitrate and phosphate creating a nitrogen and phosphate deficiency for the plants.

Target nutrient ranges:
Nitrate (N03) 5 to 10ppm
Phosphate (PO4) 0.2ppm to 0.5ppm
Iron (Fe) 0.2 to 0.7ppm
Potassium (K) 20-30ppm

Types of fertilizers:
- tablets
- spikes
- balls
- liquid

Sources of trace elements:
- Sphagnum Peat: Iron (Fe). High CEC
- Soils: Iron (Fe) other trace elements. High CEC
- Pottery clay: Iron, (Fe). High CEC
- Clay litter: Iron, (Fe). High CEC
- Vermiculite: trace amounts Iron, Potassium, Magnesium. Very High CEC

Drawbacks of Soil substrates:
When plants are removed or replanted, the soil mixture can come up with the plants and pollute the water. You are better off using a clay gravel if you anticipate moving and transplanting plants often.

The Following information is taken from "Something to Grow on", Cornell University. It is not written specifically for aquariums, but the information is very useful. I particularly like the information on CEC:
Ions Cation exchange capacity (CEC) quantifies the ability of media to provide a nutrient reserve for plant uptake. It is the sum of exchangeable cations, or positively charged ions, media can adsorb per unit weight or volume.

It is usually measured in milligram equivalents per 100 g or 100 cm3 (meq/100 g or meq/100 cm3, respectively). A high CEC value characterizes media with a high nutrient-holding capacity that can retain nutrients for plant uptake between applications of fertilizer. Media characterized by a high CEC retains nutrients from leaching during irrigation. In addition, a high CEC provides a buffer from abrupt fluctuations in media salinity and pH.

Important cations in the cation exchange complex in order of adsorption strength include calcium (Ca2+) > magnesium (Mg2+) > potassium (K+) > ammonium (NH4+), and sodium (Na+). Micronutrients which also are adsorbed to media particles include iron (Fe2+ and Fe3+), manganese (Mn2+), zinc (Zn2+), and copper (Cu2+). The cations bind loosely to negatively charged sites on media particles until they are released into the liquid phase of the media. Once they are released into the media solution, cations are absorbed by plant roots or exchanged for other cations held on the media particles.

Anion exchange capacity: Some media retains small quantities of anions, negatively charged ions, in addition to cations. However, anion exchange capacities are usually negligible, allowing anions such as nitrate (NO3-), chloride (Cl-), sulphate (SO4-), and phosphate (H2PO4-) to leach from the media.

Cation Exchange Capacities for various growing media amendments and selected media.
Material/Cation Exchange Capacity meq/100g
Perlite/ 1.5 - 3.5
Silt/ 3.0 - 7.0
Clays/ 22.0 - 63.0
Pine Bark/ 53.0
Vermiculite/ 82.0 - 150.0
Sphagnum Peat/ 100.0 - 180.0
Humus/ 200.0
Peat moss : vermiculite 1:1/ 141.0
Peat moss : sand 1:1/ 8.0
Peat moss : perlite 1:3/ 11.0
Peat moss : perlite 2:1/ 24.0

Sources: see Bunt, A.C. 1988, and Landis, T. D. 1990.

Sphagnum peat moss
Sphagnum peat moss, derived from the genus Sphagnum, contains at least 90% organic matter on a dry weight basis. In addition, this peat moss contains a minimum of 75% Sphagnum fiber, consisting of recognizable cells of leaves and stems.

Approximately 25 species of Sphagnum exist in Alberta, Canada and 335 species are present throughout the world. Sphagnum fuscum is an important species bearing many desirable traits. Sphagnum grows in northern cool regions and is also located in peat bogs found in Washington, Maine, Minnesota, and Michigan.

Many pores are present in the leaves of sphagnum; when used as growing media, as much as 93% of the water occupying this internal pore space is available for plant uptake (Peck, 1984). After draining, sphagnum peat can hold 59% water and 25% air by volume.

Sphagnum is usually characterized by an acidic pH, low soluble salts content, structural integrity, and the ability to serve as a nutrient reserve (Landis, 1990).

Although peat mosses are classified into four different groups, variation may exist within any one type of peat moss. Peats of the same classification often differ notably in quality, and even peats from the same bog taken from separate layers can possess different chemical and physical properties.

Sphagnum peat moss is classified as light or dark peat, based on its color. Light peats are characterized by a large amount of internal pore space, 15-40% of the pore space comprises aeration porosity. Dark sphagnum peat does not display the elasticity of light peat and is usually not as long lasting. Dark sphagnum peat moss maintains twice the cation exchange capacity of light peats, yet does not possess as much total or aeration porosity.

Inorganic media
Materials such as vermiculite, perlite, and sand represent the inorganic fraction often used in container media formulations. These materials generally increase the aeration porosity and drainage yet decrease the water-holding porosity of media. Inorganic components are usually inert materials characterized by a low cation exchange capacity.

Vermiculite
Vermiculite is a commonly used inorganic media component which is mined in the U.S. and Africa. This mineral, comprised of an aluminum/iron/magnesium/silicate mixture, is excavated as a material composed of thin layers. Processing includes heating the vermiculite to temperatures upwards of 1000 degrees C, which converts water trapped between the layers of the material into steam. The production of steam results in a pressure that expands the material, increasing the volume of the pieces 15 to 20 times their original size.

Vermiculite is sterile because of these high heating temperatures used during processing. Vermiculite is characterized by a high water-holding capacity as a result of its large surface area: volume ratio, a low bulk density, nearly neutral pH, and a high cation exchange capacity attributed to its structure. Because it compacts readily when combined with heavier materials, vermiculite is sometimes recommended more for propagating material than container media.

Vermiculite gradually releases nutrients for plant absorption; on average it contains 5-8% available potassium and 9-12% magnesium. This inorganic media component can adsorb phosphate - some of which remains in an available form for plant uptake - but cannot adsorb nitrate, chloride, or sulfate. Vermiculite can fix ammonium into a form that is not readily available for plant absorption. This fixed nitrogen is gradually transformed to nitrate by micro-organisms, making it available for plant uptake.

Vermiculite is manufactured in four different grades, differentiated by particle size. Insulation grade vermiculite and that which is marketed for poultry litter (which has not been treated with water repellents) has been used with some success. Vermiculite which has been treated with water repellent, such as block fill should not be used as growing media. Because vermiculite tends to compact over time, it should be incorporated with other materials such as peat or perlite to maintain sufficient porosity. It should not be used in conjunction with sand or as the sole media component, because as the internal structure of vermiculite deteriorates, air porosity and drainage decreases (Landis, 1990).

The particle size of vermiculite influences the water-holding and aeration porosity of the material. Although grade classification is based upon particle size, each grade is represented by a range of particle sizes. Note that grades consisting of larger particle sizes have a higher aeration porosity and lower water-holding porosity than grades consisting of a smaller range of particle sizes. Properties of the four vermiculite grades are shown in an associated table.

Perlite
A mineral of volcanic derivation, perlite is a second inorganic component which may be used in formulating container mixes. This chemically inert material is extracted in New Zealand, the U.S., and other countries and is usually mined by scraping the earth's surface. The processing method includes a grinding and heat treatment (up to 1000 degrees C) which results in very lightweight, white sterile fragments. As the ore is heated, internal water escapes as steam, resulting in the expansion of the material.

Perlite has a very low cation exchange capacity, low water-holding capacity (19%), and neutral pH. The closed-cell composition of perlite contributes to its compaction resistance, enhances media drainage, and heightens the aeration porosity of peat-based media (Bilderback 1982). Because perlite contains only minute amounts of plant nutrients, liquid feeding is a practical mode of fertilization. Be aware of possible aluminum toxicity in acidic media (pH < 5).

The very low levels of fluoride perlite contains is not likely to pose plant health problems. Any soluble fluoride present in a media characterized by 6.0 < pH < 6.5 will precipitate out of the media with excess calcium from sources such as gypsum, limestone, or calcium nitrate.

Although perlite has several positive attributes, it also has drawbacks. Perlite consists of many fine fragments which, when dry, can lead to lung or eye irritation. In addition, because water clings to the surface of perlite, it may tend to float in the presence of water (Landis, 1990).

Perlite contains, on average, 47.5% oxygen, 33.8% silicon, 7.2% aluminum, 3.5% potassium, 3.4% sodium, 3.0% bound water, 0.6% iron and calcium, and 0.2% magnesium and trace elements (Perlite Institute, 1983). Although a uniform categorization of perlite does not exist, individual producers of this inorganic component assign grade levels. This inorganic media amendment is sometimes recommended for use only in propagation media because of its low bulk density and tendency to compact.

In comparison with sand, polystyrene, or pumice, perlite has the greatest inner total porosity. Coarse perlite is characterized by approximately 70% total porosity, 60% of which is aeration porosity. Perlite can retain two to four times its dry weight in water, which is much greater than that of sand and polystyrene, yet much less than the water-holding capacity of peat and vermiculite (Moore, 1987).

Sand
Sand has been used as an inorganic media component to add ballast to containers. Some sands contain calcium carbonate which may raise media pH undesirably. A rise in pH may lead to nutrient deficiencies, particularly of minor elements such as iron and boron. A few drops of dilute hydrochloric acid or strong vinegar may be added to sand to test for carbonates; if bubbling and fizzing result, carbonate is present as a result of carbon dioxide production.

Sand used for container media should have a 6 < pH < 7. Sand maintains good drainage, a low water-holding capacity, and a high bulk density when used independently of other materials. Because of its shape and size, sand can obstruct pore spaces, decreasing drainage and aeration, instead of improving porosity.

Various sand particle sizes have been recommended for container media use, including ranges of 2-3 mm or 0.05 - 0.5 mm (fine sand) in size (Landis, 1990). In addition, another recommendation suggests that 60% of the particles be within 0.25-1.0 mm range, and 97% be greater than 0.1 mm and less than 2 mm (Swanson, 1989). Uniformity coefficients assigned to sand mixtures signify the amount of sand which is within a certain size range; a coefficient < 4 is evidence of a homogeneous sand mixture (Swanson, 1989). If the correct grade of sand is used, the wet ability of the media is enhanced.

Calcined clays
When fired at high temperatures, some clays, fuel ash, and shales form stable compounds that possess low bulk densities and internal porosities of 40-50%. Though calcined clays alter the physical attributes of media in a positive way, they also decrease the level of water-soluble phosphorus in the mix.

Because calcined clays are characterized by a high cation exchange capacity, fertilizer application rates may need to be modified if calcined aggregates are incorporated into the media mixes (Bunt, 1988).

Pumice
Pumice is produced as volcanic lava cools; escaping steam and gas contribute to its porous nature. This alumino-silicate material contains potassium, sodium, magnesium, calcium, and slight amounts of iron. Pumice can absorb K, Mg, P, and Ca from the soil solution and render it available for plant absorption later (Bunt, 1988).

Have questions? Email me at robert@aquabotanic.com

Aquarium Plant Nutrition

by Robert Fenner
Reprinted with permission, from Bob's website in San Diego: www.wetwebmedia.com
Aquarticles

Planted aquarium systems and their owners fall into two categories by their actions and philosophy. Extensive types take the 'natural' route of moderation: easy lighting, some attention to soil and substrate nutrient input, and "fish food fertilization". Intensive folks blast their set-ups with high intensity illumination,
regularly feed in chemical supplements, infuse CO2, forever tinkering with gear and test-kits.

Both approaches "work" for aquarists conscientious enough to study and apply adequate knowledge. Extensive ways are slower and less spectacular; intensive methods are more sure-fire, expensive and luxuriant in results; both are patently not-natural.

"Wherefore Art Thou, Essential Nutrients?"

Living aquarium plants require the same 16 elements as terrestrial plants; two of them, hydrogen and oxygen are obviously readily available. It is up to the aquatic gardener to provide the other fourteen in usable forms and concentrations, under appropriate ranges of environmental conditions (e.g. pH, temperature, lighting) to promote plant growth.

Will you have to don a white lab coat and spend your days investigating the chemical, physical and biological interactions that are conducive to plant aquariculture? Nope. As with an operational understanding of working an automobile (put in gas, check tire pressure, etc.), such success is to be had by some basic understanding and maintenance.

And with proper set-up, the task is even less daunting! As you will find, there is no great consensus on whether to adopt intentional supplementation. However, for almost all situations, minimum nutrient requirements are met through water, substrate and fish food feeding.

Here we'll present an overview on the major, or macro-nutrients, those of smaller concentration, the minor or micro-nutrients, sources and factors influencing their availability.

The Major Mineral Nutrients of Plants

As for the label on "complete" terrestrial fertilizer bags the first three elements necessary to aquatic plants are N, P, K, Nitrogen, Phosphorus & Potassium. To these you can add Carbon, Oxygen, Hydrogen, Calcium, Magnesium, Sulfur and I'll throw in Iron.

The Minor, or Micro-Nutrients:

Include Zinc, Copper, Manganese, Molybdenum, Boron, Chlorine, and possibly sodium.

Factors Influencing & Providing Nutrients:

The abundance of all nutrients for aquatic plants in the wild has been noted many times in the literature (Horst). Likewise, the availability of all chemical needs from foods (Walstad), as well as contributions from various waters, mineral substrates (gravel, sand), and soils.

In captive systems all these source mechanisms interplay to provide essential (and not) media in differing proportions. The conscientious aquatic gardener is aware of origin contributions, testing; adjusts for the same through water changes, possible supplementation.

But the presence of essential materials in agreeable proportions is not the end-all of considerations; other factors, light, temperature, pH, dissolved oxygen and more figure into the form and usability of these materials by living plants.

How do these materials make their way into photosynthetic life? Plants absorb water and carbon (as carbon dioxide) in molecular form; all other essential nutrients as charged ions. There is evidence that plants can effectively deposit the necessary heavy metals (e.g. iron) and even absorb undissolved nutrients
from the substrate.

Here are some of the 'highlights' in contributing sources and factors affecting plant nutrients.

Water:

"It's the water, and a lot more". Depending on your water source, use of reverse osmosis, deionization or even distillation, your mains or tapwater may play a significant role in providing mineral nutrient to your aquatic plants. The water authority or other agency involved in this utility can provide you with an analysis of what's to be expected in your tap.

Some aquarists prefer to start with water that has had most everything other than the water itself removed, and add back their desired solids. For most localities and set-ups this is unwarranted; other less-extreme steps to ameliorate hardness, etc. being simpler and less expensive.

Fish Foods:

Also known euphemistically as "organic fertilizer". With minimal fish stocking and outside feeding of fresh and prepared foods, almost all systems receive enough of all necessary macro and micro-nutrients to support plant life. For rapid, sustained luxuriant aquarium plant growth, however, outside supplementation and soil addition are called for.

Substrates and Soils:

These topics are too wide for complete treatment here. Please see other pieces in this series for elaboration.

Basically, substrate (sand, gravel) acts in three ways, as a mineral source, anchoring media, and bio-habitat in aiding or denying plant growth. The proper size, depth, shape and composition of substrate is therefore of consequence.

Soil(s) make available organic and inorganic nutrients, act as catalysts, and support the interstitial bio-chemico-habitat. The benefits of their appropriate use are undeniable. Cation exchange provided by clay particles' negatively charged sites temporarily hold and make available positively charged ions (e.g. Ca2+, K+, Na+). This is why some clay is essential in aquarium soil.

Light and Carbon

Sufficient quantity, quality and duration of light are obviously fundamental; as is adequate carbon, generally measured as CO2. Without these inputs, no photosynthesis, no plants.

Carbon dioxide plays another intimately important role in alkaline-carbonic pH balance. Much more about this in a later article. For now, here are some very useful Internet links to CO2 use/gear:

http://www.wcf.com/
http://www.geocities.com/bwe407/poll_nn4.html
http://www.csd.net/~cgadd/aqua/diy_co2rig.htm
http://www.geocities.com/nguyenhg/

Temperature

The "average kinetic energy", aka thermal content of a system controls all rates of reaction, chemical, physical, and the sub-set within we call biological. Plants like animals, have optima and ranges of temperature tolerance. You are charged with knowing and accommodating your species mix to its regime.

pH & More:

The acidity/alkalinity of a system is a large determinant in the availability of nutrients for plant growth. Yes, this is a "plug" for monitoring, setting up and doing maintenance to produce the "dynamic equilibrium" of a steady, moderate substrate and water pH.

Placing and keeping pH is effected by substrate and filter media choices, water chemistry manipulation and exchanges.

Circulation & Water Changes

Movement in and periodic partial removal and replenishment of water aid in destratification, removal of accumulating "heavy water", promotion of redox potential, and replacement of minerals.

In the wild, currents, thermal and wind turnover, rain and runoff take care of these concerns; in captive aquatic forests, it's up to you and your filtration and mechanical circulation. Ideally water would be continuously entering and leaving your systems, making nutrients available in a consistent manner and carrying away undesirable material... realistically, weekly changes will approach suitable conditions; coupled with other (substrate, water, soil) factors.

Supplementation:

All the above taken into account, should you engage in chemical augmentation; liquids, granular fertilizers? Even CO2? For years before these innovations, aquarists kept splendid planted aquariums... many folks were not as fortunate however. With supplementation, success is practically guaranteed. What types
of supplements, if any, should you employ?

If you haven't heard it enough, NEVER USE TERRESTRIAL FERTILIZER IN AN AQUARIUM. Per the above spiel, you can see that these are too concentrated and wrongly formulated for aquarium use; too much fertilizer is dangerous, it will poison your system. This applies to all land-plant fertilizers, including organics like urea and bloodmeal.

The most widely available aquarium plant fertilizers are liquids and pellet/tablets. Liquids are ideal for floating and un-rooted plants and have the advantage of low and diffuse concentration; minimizing the likelihood of 'burn' and algal bloom. Tablets and pellets are better for their longer action and targeted placement for rooted aquatics.

All types of augmentation, fertilizer, soil, require periodic replacement. Liquids are best scheduled for weekly or more addition in conjunction with water changes.

All these forms of supplementation vary in their specific chemical formulations, and each has their league of supporters and detractors. I myself encourage using just an appropriate soil and occasional iron prep.. For the uninitiated, if you're so inclined, you are further urged to utilize a "complete" fertilizer, one with all macro- and micro-nutrients purposely included.

Know the products you are using and their limitations. In particular understand that there are interactions between the chemical species present and the ones you are adding. Once again, the value of frequent partial water changes can be seen as a mechanism for replenishing mineral salts and diluting excess dissolved solids.

Close:

Plants require a number of elements for metabolism and growth that they obtain from the water, soil (if any), substrate, cycled fish food, fertilizer (if added), and air. In nature most of these are provided by the weathering of rock; in aquariums, depending on the rate of growth desired, they're augmented on a periodic basis via the sources listed above.

The major chemical nutrients of land and aquatic plants are identical; the form and ways in which aquatics take them up however are different. These differences are important to the aquatic gardener in approaching methods of appropriate fertilization.

Should you utilize chemical supplementation? With most set-ups this is unnecessary to support growth. On the other hand, most luxuriant systems utilize soil, CO2,intense lighting, and chemical supplementation.

Bibliography/Further Reading:

Baensch, Hans A. & Rudiger Riehl. 1993. Aquarium Atlas V. 2. Rare Fishes and Plants. 1,212 pp. BAENSCH, Germany.

Fuchs, Lothar. 1975. Tips for the controlled fertilization of plants. ADI 3:4/75.

Horst, Kaspar. 1977. Aquatic plants; Interpretation of our field studies for use in the aquarium. ADI 4(1977), #18.

Horst, Kaspar. 1978. Tropical streams are being permanently fertilized. ADI1(1978) #19.

Jeffries, Owen R. 1990. Correct fertilization of tropical aquatic plants. FAMA11/90.

Jeffries, Owen. 1995. Substrate and liquid additives for improved plant growth in aquariums. FAMA 6/95.

Kassebeer, Gerd. 1988. An analytical course for aquarists; IX. Balance sheet of aquarium plant nutrients. Today's Aquarium-Aquarium Heute 2/88.

Kelly, Jim. 1996. Notes on key soil characteristics for aquarists. TAG 9(4):7,8/96.

Krumbholz, Paul. 1993. The Krombholz kronicles: mineral nutrition of aquatic plants. TAG 6(5):9,10/93.

Pedersen, Peter L. 1994. What about phosphates? TAG 7(1):1,2/94.

Pooler, Gene. 1996. Playtime in the fish tanks (On iron use). Tropical Breeze, bulletin of the San Diego Tropical Fish Society, Winter 96.

Raven, Peter H., Evert, Ray F. & Helena Curtis. Biology of Plants, 2nd ed. Worth Publishers, NY. 685 pp.

Spiers, Dale. 1991. Plant growth and iron. TAG 4(1):1,2/91

Walstad, Diana.1992. Aquatic plants prefer ammonium to nitrates. TAG 5(6):11,12/92, and FAMA 4/94.

Walstad, Diana 1993. Plant nutrient availability in the aquarium. FAMA 5/93.

Walstad, Diana. 1994. Fishfood as a source of plant nutrients. TAG 7(2):3,4/94.

The Role of Photosynthesis in the Aquarium

by Robert Paul Hudson
from Robert's web site in Salem Oregon: Aquabotanic.com
Aquarticles


Photosynthesis is the process by which plants use the energy of light to convert carbon dioxide and water into glucose, and the by-product released is oxygen on which most life depends. In the absence of light, the process of respiration is the opposite of photosynthesis. Food substances are broken down in the presence of oxygen to release energy as heat. Carbon dioxide is produced and released as a by-product. These processes are a vital part of the plants' growth and the introduction of high intensity light and carbon dioxide produces a significant increase in photosynthetic activity thus creating a boost in plant growth and vitality. Active photosynthesis is what makes the difference between healthy aquarium plants and those that are merely surviving.

Glucose, a carbohydrate, is the fuel formed from photosynthesis used to build leaves, flowers, fruit, and seeds. Excess amounts are stored in the plants' roots, stems, and leaves in the form of starch that can be drawn from as a reserve. Glucose is also converted to cellulose, which is used as a structural material in the building of cell walls.

Plant photosynthesis occurs in leaves and green stems within cell structures called chloroplasts. Each leaf has tens of thousands of cells, and each cell contains 40 to 50 chloroplasts. Each individual chloroplast is sectioned by membranes into disk shaped compartments called thylakoids. Embedded in the membranes of the thylakoids are hundreds of molecules of chlorophyll, a light trapping pigment required for photosynthesis. Enzymes, which are additional light trapping pigments, are also present in the membranes.

Photosynthesis is a very complex process that is still not fully understood. In simple terms there are two stages. In the first stage, the light dependent reaction, the chloroplast traps light energy and convert it into chemical energy contained in two molecules: NADPH, nicotinamide adenine dinucleotide phosphate, and ATP, adenosiue triphosphate. In the second stage called the light-independent reaction, NADPH provides the hydrogen atoms that help form glucose, and ATP provides the energy for this and other reactions used to synthesize glucose. This is all the result of the literal meaning of the term photosynthesis, to build with light.

Two things must be present for this to happen: light and carbon dioxide. Many of the plants we use in aquariums come from a natural habitat where they grow out of the water, or have growth floating at the surface where light is more intense and carbon dioxide is taken from the atmosphere, therefore without elevated light and carbon dioxide levels these plants cannot reach a proper photosynthesis rate. Plants that grow their entire life submersed have evolved to grow in conditions where both light and carbon dioxide may be hard to come by. Some plants can absorb carbon dioxide from sediment at their roots. Sediment may be rich in carbon from decaying organic material and bacteria that goes thru a similar process releasing CO2. Another source for some plants in alkaline water is stripping the carbonic molecule in the water.

Nutrients also play a role in the plants ability to photosynthesize. For example, potassium regulates the opening and closing of stomates (the pores through which leaves exchange carbon dioxide (CO2), water vapor, and oxygen (O2)). Proper functioning of stomates is essential for photosynthesis, water and nutrient transport, and plant cooling. Sugars produced in photosynthesis must be transported through the phloem to other parts of the plant for utilization and storage. The plant's transport system uses energy in the form of ATP. If potassium is inadequate, less ATP is available, and the transport system breaks down, and the rate of photosynthesis is reduced. Another example is chlorophyll. In order for it to be present in the leaves, iron must be present. If iron is not present the leaves loose their green pigment and become yellow, and photosynthesis is interrupted.

What does this all mean for the hobbyist and the planted aquarium? By understanding the basics of how this process works, we can recognize signs of success or ways to improve conditions for better plant growth and a healthier environment.

Duplicating natural habitats in an aquarium where plants take CO2 from sediment is difficult and not fully effective, but not impossible, however not all the plants we use will respond to this. Much more favorable results are achieved by having an intense enough light source along with adding a source of carbon dioxide to the water which has immediate affect.

Very soft water is not conducive to the addition of carbon dioxide because sufficient carbonate hardness is needed as a pH buffer. The alternative source would be sediment from the substrate or gravel bed, which is achieved by allowing mulm to accumulate and not cleaning the gravel on a regular basis. While this may seem to go against what we have been taught in basic aquarium care, it can be done safely within reason. Mechanical filtration, occasional water changes, and good circulation along with a low to moderate fish load will keep the system balanced. Plants should be left undisturbed as much as possible. Constant uprooting of plants or re-arranging the substrate will release mulm and possible pathogens into the water column. At initial setup, a small amount of Sphagnum peat added to the bottom layer of the substrate will provide enough organic material that while decomposing will release small amounts of carbon dioxide.

"Pearling" is the term used to describe the plants releasing oxygen during the light hours and is an indicator of the photosynthetic rate of the growing plants. Under subdued lighting you are much less likely to see significant streams of bubbles. Increasing light intensity, (not duration) coupled with increased CO2 levels will dramatically raise pearling activity. The more intense the streams of bubbles the faster the photosynthesis rate and a sure sign that all is healthy. A CO2 level of 25 to 30ppm provides the most optimal growth.

The Open Aquarium

by Claus Christensen
Claus is Managing Director of Tropica Aquatic Plants, of Denmark
Aquarticles

The open aquarium, without the top glass and with the lamps hanging from above, provides a new dimension of the traditional aquarium and it allows plants to produce an emergent inflorescence. Does it cause humidity problems in our homes? Will the leaves of emergent plants dry out? What will happen to the fish?

The open aquarium is my favourite aquarium! It provides new dimensions for the aquarium and the living room. We can observe the leaves of floating plants, flowering aquarium plants such as Nymphaea (water lilies), and a lot of other aquarium plants that are amphibious and grow out of the water providing great ornamental effects. In addition, opening the aquarium offers more possibilities for exciting illumination.



But this beautiful aquarium may affect the indoor climate much more than a traditional aquarium:
Relative air humidity
A frightening example was an aquarist with an open aquarium of 800 litres in a room of 16 m². He had discus in the aquarium and the water temperature was 28°C (82°F). Problems cropped up because of the large aquarium and the huge evaporation caused by the relatively great difference in temperature between the room and the aquarium. The wallpaper became mouldy and the windows were constantly misty.

But usually open aquaria do not cause problems with damp if the following are observed:
- The surface of the aquarium should not exceed 2% of the room area. Thus, in a room of 40m² the aquarium should not exceed 500 litres.
- The difference in temperature between water and air should not exceed 5°C (9°F), to keep evaporation at a minimum. We have seen problems in unheated rooms during the winter because evaporation increases tremendously with the difference in temperatures.
- Make sure that the room is frequently aired - this is advisable anyway and it ensures a healthy indoor climate.
- Finally, floating plants or plants with floating leaves will help to lessen evaporation because they create a boundary layer of relatively stagnant air!
If these precautions are taken, the relative humidity will increase only by about 5%.



I have asked scientists working with health and air humidity, and recent research has shown that people cannot feel variations of 30-70% in relative humidity. When the air is recognized as dry or moist within this range, it is caused by other factors such as high temperature, dust, or gases released from materials in the room, e.g. building materials, carpets, paint, etc. Thus, people usually do not feel the increase in relative humidity that an open aquarium causes. For example, one person emits 2.5 to 3 litres of water per day (breathing, sweat, showering, cooking), so if an open aquarium of 800 to 1000 litres evaporates some 15 to 20 litres per week, it simply amounts to an extra person living in the home.

Some allergists are very sensitive to microorganisms and the substances they may emit. But recent research has shown that growth of microorganisms is independent of the actual relative humidity. Microorganisms rely on the microclimate, which is created by the fabrics on which they live and not the actual relative humidity as such. Aquaria in general - traditional as well as open - have been examined in relation to allergy, and a few cases have shown some negative effects, but not due to increased relative humidity. They have all been caused indirectly by problems created by leaky tanks, which caused for example growth of moulds in the carpet. In really rare cases people have developed allergy to red midgets (chironomids), an allergy caused by the red protein haemoglobin.

From the research on indoor climate it may be safe to conclude that the effect of open aquaria may be purely positive - a relaxing effect, psychological in nature.



Illumination
Different types of lamps can be used for the open aquarium. A few lamps on the market spread too much light out into the room and not down into the aquarium where it is needed for plant growth. This may dazzle people in an otherwise dark room, and it may cause a cool gleam in the room. Such problems are often caused by hanging the lamps too high, but may also be caused by a reflector that is inefficient in concentrating the beam. The lamps must be lowered to a point where all the beams are falling onto the water surface.

In Germany they produce metal halide lamps designed so that only very little light escapes the open aquarium. Small low-voltage halide spotlights (very popular at the moment) can provide fantastically beautiful illumination on individual plants. These are particularly ideal for slant illumination from the front screen inwards, and often give new glowing colours to both fish and plants because of new reflections. However, these lamps are usually insufficient as growth lights for aquaria larger than 100 litres.

Amphibious plants
The leaves of plants growing out of the water may tend to dry out if the relative humidity of the air is too low, or the lamps are placed too close to the water surface. New shoots may be sprayed with water a couple of times each day, after which they usually do fine without any problems. Some plants, however, never adapt to the dry indoor air.

Many plants sold for aquaria - about 50% - are especially well suited for open aquaria. I will just mention a few of my favourites: Echinodorus grandiflorus, E. cordifolius and Echinodorus 'Tropica Marble Queen'. The 'Tropica Marble Queen' develops a heavily marbling above water and is very resistant to drying. All species of Hygrophila and floating plants will show in all their glory only in the open aquarium. Even obligatory submerged plants, such as Vallisneria, are better viewed from above.


The fish
Some fish may simply jump out of the aquarium. This is partly avoided by using a lot of floating plants. They provide a great ornamental effect but they may also make some fish feel more secure. However, some fish are very liable to jump out no matter what you do, and they should of course be avoided. Tip: glue on a horizontal border of glass (5 cm wide) all around, and this may prevent even the most jumping of fish from landing on the floor.

Therefore, my answer is "you may safely build yourself an open aquarium!"

Setting Up a Planted Aquarium

by Karen Randall, of Boston, Mass.
Karen edits the magazine of the Aquatic Gardeners Association.
Aquarticles

The Tank:
A tank between 10 and 30 gallons is the best size for beginners. Smaller tanks can be managed, but require more attention to detail. Larger tanks often take up more space than can be spared and are more expensive. Certainly, if you have a tank that is outside this range, don't hesitate to use it, but be aware that these instructions will have to be modified.
If possible, use a tank that is longer than it is tall. Tall, narrow tanks and those of unusual shapes are difficult to light adequately, and are also hard to work in. Some of the best tanks are:
Standard 10 gallon, standard 15 gallon, 20 gallon "long", 20 gallon "high", 29 gallon "high", 30 gallon "long".
All of these tanks can be outfitted with commonly available aquarium equipment.

Other equipment and supplies:
- Enough good quality fluorescent lighting to reach at least 2 watts per gallon. An exception to this rule is the 10 gallon tank. This tank is small enough and shallow enough that you can usually get adequate growth of shade tolerant plants using a single 15 watt bulb as long as the bulb is less than 1 year old, and of good quality. Except for the 29 gallon "high" tank, all of the other tanks mentioned can be adequately lit with two bulbs of the largest size that will fit on the tank. i.e., two 24" 20 watt bulbs over the 20 gallon tanks, and two 36" 30 watt bulbs over the 30 gallon tank. For the 29 gallon size, you will need three 24" 20W bulbs for adequate light. Aquarium strip light fixtures come as either double or single bulb fixtures. You can use any combination of single or double bulb fixtures that will meet your needs.
Some good brands of bulbs are:
More expensive: VitaLite Pennplax Ultra-Trilux Triton
Less Expensive: GE Chroma 50 Phillips Ultralume 5000 Phillips Daylight
- Glass canopy
- Heater: 150W heaters are probably adequate for the 10-20 gallon tanks, 200W heaters will be adequate for the larger tanks. Buy a good quality submersible heater. Don't skimp here... a tank is left unattended too often to risk your plants and animals to a faulty thermostat!
- Thermometer: Any aquarium thermometer will do, but I prefer the stick-on-the-glass liquid crystal type for several reasons. They are unobtrusive, but easy to read, they are inexpensive, and most are marked with both Fahrenheit and Celsius scales which makes them another useful learning tool.
- Filter: Do not use an under gravel filter or other air driven filter in a planted tank. It will drive off needed CO2. Use either an internal or external power filter. There are many good ones on the market. My preference is for those that have rinsable, reusable filtration media rather than those with disposable "cartridges". They are less expensive to maintain, and more environmentally friendly. Any good pet shop can tell you which size filter to get for your particular tank, but it is better to slightly oversize the filter rather than skimping. A couple of reliable brands of outside power filters are Marineland and Hagen. Duetto internal power filters are excellent in a number of applications.
- CO2 Generator: See specific directions for making a yeast reactor.
- Electrical equipment: Use a heavy duty power strip to provide power for your aquarium equipment. If you cannot locate the tank near an outlet, use a heavy duty extension cord. You will also need a light timer (like the ones used when people go on vacations) to turn the tank lights on and off each day.
- Support: Remember that an aquarium is heavy! Filled, it will weigh close to 10 pounds per gallon. 10 gallon tanks can be placed on a sturdy table. Larger tanks really need a properly designed aquarium stand.
- Gravel: Use fine non-coated natural color aquarium gravel. It should be between 1-3 mm. in size, and not contain calcium carbonate bearing rock. You can test this by placing a drop or two of muriatic acid (available at the hardware store) on a sample of gravel. If it foams, don't use it.
You will need about a 25 pound bag for a 10 gallon to 20 "high" tank, you'll probably need a 50 pound bag for the larger tanks.
- Laterite: This is an iron rich tropical clay that will serve as the nutrient base for your plants. Your local pet store will either carry it, or can order for you.
- Another very good alternative for the substrate of a planted tank is Seachem Flourite. This product is attractive, easy to use and grows plants very well. You do not need to add laterite or other materials to a Flourite substrate; it can be used as-is.

Tank Set Up:
These directions make the following assumptions about your tap water:
- KH: (carbonate hardness) reading of between 3 and 8 KH. (test kit, or have the pet store do the test for you)
- Phosphate: below .5 mg/l (test kit, or water department report)
- Nitrate: Below 10 mg/l (test kit or water department report)
If your tap water does not fall within these parameters, you will need to make some modifications. Contact your pet shop for specific suggestions.

- Place the tank on a stable, level surface. If there is even the slightest unevenness in the support, the tank can develop leaks. If you have any question about the surface that you are placing the tank on, place a couple of sheets of corrugated cardboard, or a sheet of styrofoam under the tank. Any excess can be trimmed off close around the tank. This is also a very good idea if you are using an open metal aquarium stand. The styrofoam will prevent heat loss from the bottom of the tank.
- Before you go any further, fill the tank with water, wait twenty minutes to test for leaks and empty. This may seem like an annoying waste of time, because most tanks will not leak. But believe me, if you've bought the one that does, you will be much more annoyed if you find out about the leak after the tank is fully set up and running.
- Install the thermometer, filter and heater, but don't plug anything in yet. Set your heater to approximately 76F unless you will be using fish that specifically need warmer (like Discus or Rams) or cooler (like Goldfish or White Clouds) water.
- Rinse your gravel under running water until the water runs clean. The better you rinse your gravel, the less cloudy the tank will be when it is first filled. Mix laterite into damp gravel in a bucket. Use enough gravel to make an approximate 1 to 1 1/2" bed in the bottom of the tank. Be prepared, this step is messy! You might want to wear rubber gloves. While you want the gravel to be damp, try to avoid introducing any standing water to the aquarium.
Note: Seachem Flourite will NOT rinse completely clear - That's OK, it is an important property of the substrate, and if the tank is filled slowly, there will only be minimal temporary clouding of the water.
- Next cap the substrate with enough plain rinsed gravel to bring the total depth of the substrate to 3". With a 10 gallon tank, you can get by with a gravel bed of 2 - 2 1/2". Level the front edge of the gravel carefully so that it looks neat once the tank is filled.
- If you are planning to use driftwood or any decorative rocks, they can be placed in the tank now.
- The next step is to fill the tank about 3/4 full of water. The water should be between 70-80ºF. The exact temperature is not critical, but you want to be within a range that will not harm the plants. How you fill the tank will make the difference between a tank that will be crystal clear by morning, and one that can take a week or longer to settle down.
- Get a shallow saucer or bowl and place it on the gravel. VERY slowly, TRICKLE the water onto the saucer. Let it gently overflow, filling up the tank. When the saucer is completely submerged, you can speed up the flow a little, still aiming the flow at the plate. If this is done carefully, the water should be quite clear from the very beginning. If you aren't careful enough, don't panic. The tank will look cloudy for a few days, but it will eventually settle out.

When the tank is about 3/4 full, it's time to plant:
Here is a list of good sturdy beginners' plants. Those with a * are particularly good "nutrient sponges", and should be emphasized in a start-up tank:

Common Name - Scientific Name - Origin

Java Fern - Microsorum pteropus - Asia
Java Moss* - Vesicularia dubyana - Asia
Water Sprite* - Ceratopteris thalictroides - World Wide
Water Wisteria* - Hygrophilla difformis - Asia
Small Leafed Hygro* - Hygrophilla polysperma - Asia
Giant Hygro*- one of several Hygrophilla sp. - Asia
Willow Leaf Hygro* - Hygrophilla angustifolia - Asia
Valisneria or Tape Grass - Valisneria sp. - New World and Africa
Sword plants - Echinodorus sp. - New World
Rotala rotundifolia* - same - Asia
Milfoil or Foxtail - Myriophyllum sp. - World Wide
Ambulia - Limnophila sp. - Asia
Fuzzy Duck Weed - Salvinia sp. - New World
Anubias barteri - same - Africa

All of these plants should be readily available. If your local pet shop doesn't regularly stock them, they should be able to order them for you from their supplier. Beware of choosing plants for your aquarium just because they look pretty. Many pet stores sell a number of terrestrial plants as aquarium "decorations". These WILL NOT survive long term, and as they deteriorate, they will add to the waste materials in your tank. There are also a number of very tempting red plants for sale. While some of these are good aquarium plants, most need very strong light, and are a little more sensitive than the species listed above.

- "Rosette" or "crown" plants are planted individually in the substrate. Make sure that the crown itself is above the substrate surface. Only the roots should be buried. This is also true for the thick rhizome of Anubias plants.
- Stem plants are usually sold in rootless "bunches". They should be removed from their elastic band or lead weight, and planted no more than 3 stems at a time. They will quickly root themselves under good conditions. If they tend to float out of the substrate in the beginning, you can place a few small stones around the base. Another trick is to leave them floating for a week or so. Usually they will have begun to develop roots in that period of time, and it will be much easier to keep them down.
- Water Sprite can either be left floating, or planted in the substrate.
- Salvinia (and several other similar small plants) are floaters. Remember that they increase quickly, and remove most of them when you do other tank maintenance. Don't let more than 1/3 of the water surface become covered with these plants.
- Java Moss can be either left loose, or tied (or stapled) onto driftwood.
- Java Fern does not usually do well with its roots in the gravel. It is best to tie or rubber band this plant to rocks or driftwood. You can even just wedge some in between two stones.

Any plants that come in plastic pots should be removed from the plastic pots, (this may require cutting the pot away with scissors) and have the rockwool removed from their roots before planting. The rockwool is used to grow the plants, and protects the roots during shipment, but it may contain hydroponic solution which can cause algae problems in the aquarium.

Now that the tank is fully planted, it is time to fill it to the top.
It should be filled to above the plastic "frame" and close to but not touching the lip that holds the cover glass. This is where the water level should be kept at all times for several reasons. If you allow the water level to drop, the water returning from the filter will splash down onto the surface, creating a great deal of turbulence. This will drive off the CO2 that we are trying to add to the tank. Additionally, the greater distance that light travels through the air, the more it will scatter, and the less that will reach your plants within the tank. On a very brightly lit tank, this is a minor consideration. With a moderately lit tank such as we are setting up here, we need to conserve our resources! Do not, however, go in the opposite direction and keep the tank full enough that the water touches the glass. This would completely stop gas exchange, which is not a good idea either!
The last thing to do is to plug in all your equipment, and see that the light timer is set for about 12 hours on and 12 hours off. You're in business!

Wait at least one week, preferably two before adding fish to the tank.
At the two week mark, you can add algae eating fish. My favorites are Otocinclus, which should be purchased in groups of at least 3, and Siamese Algae Eaters (Crossocheilus siamensis). Siamese Algae Eaters are not available in all areas of the country. They will also eventually get too large for a 10 gallon tank and will need to be traded back in to the pet store for a new, smaller specimen. If you can't find SAE's, Bushy Nosed Cats (Ancistrus sp.) are a reasonable alternative, as are some of the Clown Plecos. (Peckoltia sp.) Ghost or Glass shrimp are also good algae eaters, and are interesting to watch, but will most likely become fish food once the tank is fully populated. You'll have to decide whether your kids (and parents!) can handle that or not. Farlowella catfish are excellent algae eaters for larger tanks.
Do not feed your algae eating residents for another two weeks. Their job is to eat any algae as it appears. They won't do that if you make life too easy for them.
At the end of the first month, your plants should have settled in and be growing well. The algae eaters should be keeping up with most algae, although it is still normal to need to clean the glass from time to time. At this point, you can start stocking your tank with its final residents. You can also begin your regular maintenance routine.
Don't fall into the trap of overstocking the tank, either in terms of numbers of fish or numbers of species. In a 10 gallon tank, 3-4 species is more than adequate, while the 20-30 gallon tanks can accommodate a few more. The fish will display more natural behaviors than if the tank is stocked with the "Ark mentality" (two of these and two of those).
My personal preference is to stick with compatible fish from a single geographic area. But of course, this is a matter of personal preference, and as long as the species chosen are compatible, and occupy different areas of the tank, the fish will not care that they come from different continents! If you want to be completely true to your geographical theme, you can choose plants native to those areas as well.
If possible, pick one species that stays near the surface, one species that is a mid water swimmer, and another that stays near the bottom. Make sure you buy multiples of any schooling fish. An absolute minimum number of any schooling species is 3-5 individuals, 12 or more will allow true schooling behavior.
Steer clear of fish that are known to be scrappy unless you have an experienced aquarist that can help you plan a community around them. There are so many beautiful, interesting and peaceful species available that it makes no sense to set yourself up for problems. Also avoid fish that are known plant eaters.
Once you have decided on the population mix for your tank, add them slowly. Bring in one species the first week, another the next until the tank is fully stocked. This will allow the good bacteria in the filter to adjust slowly to the increasing bioload.

Rev. 01/2002

Keeping Aquarium Plants By Someone Who Has been Lucky Keeping Aquarium Plants

By Al Ridley
First published in the newsletter of The Kitchener-Waterloo Aquarium Society, Canada
Aquarticles

I was surprised at the number of people that approached me last meeting about plants. I have always enjoyed keeping them as have several of my hobbyist friends but there never seemed to be much passion with the exception of a couple of people. In this article I will tell you a little about keeping and growing plants successfully, or at least what makes it successful for me.

First of all, let's discuss the need for plants in the aquarium. An aquarium without plants is like a home without furniture. It is liveable - but ugly, uncomfortable and inefficient. Live plants aid in displaying fish giving them shelter and security. They provide shelter for baby fish, shy fish, weak fish and females giving birth. They serve as food for vegetarian fish. They help prevent green water by competing with the algae for nutrients in the water. Plants absorb carbon dioxide and wastes and add oxygen to the water. They increase the surface area for algae, tiny worms, rotifers and protozoa to grow and in turn provide live food for the fish in the tank. And you thought that they just looked nice.

I prefer to pot most of my plants. The method is very simple and does not take a lot of time or effort. First you need some sort of pot. This could be the plastic pots that your garden plants come in, yoghurt containers, the bottom cut off a plastic pop bottle or small clay pots that you can buy at most nurseries. If it is a plastic container, make sure that it is not toxic to your plants or fish. Next get a bucket and add some water to it. Into the bucket add some potting soil. I prefer to use Hillview Potting Soil as I have found that it is pure soil with nothing added. The reason for mixing the soil and water together first is that if you do not saturate the soil and drop the pot into the aquarium, you take the chance of the air in the soil exploding to the surface and making a real mess of the aquarium. Believe me when I say that it can be very frustrating if you rush the job and end up with a big mess. It has happened to me too many time to count. Once the soil is moist (not like soup, more like Play Doh), fill your potting container 2/3rds full of soil. Take your finger and push it into the soil to create a small planting hole. Take your plant and carefully insert the root system into the hole. Carefully fill the hole from the sides, then add aquarium gravel to top up the container. Gently pull the plant upward until the crown of the root is just visible at the gravel surface. I usually have a bucket of aquarium water close by so that I can now submerse the potted plant for a few minutes prior to adding it to the aquarium. This will allow any trapped air to escape and possibly prevent the grief that I was talking about earlier. Now you can place the potted plant into the aquarium and enjoy. The potting soil will give the plant that extra goodness and it shouldn’t be too long before the plant begins to thrive and propagate.

What do I like about potting my plants? I guess the biggest thing is that like most plants, they do better if you leave them alone. Potted plants can be moved around easily without disturbing the root system. I have a Cryptocoryne wendtii that has been potted for almost four years now. It goes through stages of fullness and dying back but always seems to do well. There will come a time very shortly that I will remove the plant, separate the runners and replant it in many other containers. Once the pot becomes root bound (you will see the roots growing upwards out of the pot), the plant needs to be repotted.

Lighting is the most important prerequisite for successful plant growth. I have heard many different opinions on how much light is needed but my rule of thumb is one and a half watts per gallon. Most of my tanks are on home made stands that have the double four-foot fluorescent strip over them. I have two aquariums that are on their own stands, My 180 gallon aquarium has two, double four foot fluorescent strips (160 watts) and my 50 gallon has one, double four foot fluorescent strip (80 watts). I use the regular Cool White tubes, that you can buy relatively inexpensively at most hardware stores, along with the Plant and Aquarium tubes that sell for around $6.00 at the same stores. Most store bought canopies are not capable of providing enough light to keep most aquarium plants healthy so be sure to ask your store dealer for suggestions if keeping plants is your focus.

I have also experimented with different types of lighting. I have had good success with both compact fluorescent bulbs and par 20, 50-watt halogen bulbs. Don’t be afraid to try different light sources. Plants will recover very nicely even if they look rough.

Pruning your plants will also help them to grow healthy and strong. Carefully remove dead or dying leaves and any leaves that are damaged or have holes in them. The plant uses a lot of energy to try and repair these leaves, energy that could be used to produce new, lush growth.

If your goal is to keep a natural aquarium, live plants are a must. If you just want to have a nicely decorated aquarium, live plants can be used with plastic plants and rocks to beautifully aquascape your aquarium. Remember that the key is to be patient and to provide the right conditions for the plants that you are keeping.

So You Want to Grow Aquatic Plants

by Olga Betts
First published in the newsletter of The Vancouver Aquatic Hobbyist Club
Aquarticles

Some aquatic plants will grow under some conditions all of the time. In other words, anyone who wants to can grow aquatic plants.

Here is the secret: Grow aquatic plants that suit the conditions of your aquarium.

Know your plants. Buy a simple book about aquatic plants such as: Aquarium Plants Manual published by Barron’s. This is a good and inexpensive book to get you started; available in many aquarium stores.

Aquatic plants are just the same as those that grow in a garden. Some prefer lots of sun, some prefer shade, some like rich soil, others sandy, poor soil. Of course, all aquatic plants like lots of water but the beauty of that is — you don’t have to water them!

Calculate how many watts of light per gallon of water you have. You can grow most aquatic plants with at least 2 watts per gallon. Some will do fine with less; some will do better with more.

The typical aquarium comes with one light in the hood (aquarium cover). If you would like to grow aquatic plants spend the money to get a fluorescent hood as fluorescent lighting more closely emulates the sun than does incandescent lighting. A starter tank is generally set up with a gravel substrate with or without an under-gravel filter. You will be able to grow aquatic plants either way. Medium or fine gravel is better than chunky.

Plants to buy for low-light, regular substrate aquarium are:
Java fern (Microsorium pteropus) - attach this plant to wood or porous rock
Cryptocoryne wendtii
Hornwort (Ceratophyllum demersum)
Wisteria (Hygrophila difformis)
Hygrophila polysperma
Water fern (Ceratopteris thalictroides)

These will give a nice variety of leaf shape and green colours. Hornwort and the water fern can be planted or floated. Remember that floating plants block light to those underneath. Java fern and Cryptocorynes will live and grow slowly in low light. The Hygrophilias will grow quickly towards the light getting leggy and losing leaves on the lower stem. However, if they are pulled up regularly, trimmed and the tops planted back they will grow quickly enough to look good.

All plants need nutrients. These can be added to the water and also come from the fish in the aquarium. Plants use carbon dioxide, ammonia and ammonium as well as nitrates as fertiliser so fish waste is well utilised. The debris that naturally accumulates in the gravel will fertilize the plant roots. A commercial fertiliser can be added at water changes. The best advice here is err on the low side. You can always add a little more. It is hard to remove once in the tank. Too many nutrients will mean algae that you don’t want.

Water quality makes a difference. Do you know how hard your water is? Water in the Vancouver area is generally very soft. Plants like this better than hard water but they need some minerals such as Calcium and Magnesium that affect the hardness of the water. A commercial fertiliser will add traces of these that may be adequate for your needs. Buy some fertiliser tablets for the substrate and put pieces of these around the plants, especially the Cryptocorynes.
As your plants start to grow and do well you may find that some out-compete the others. You may want to eliminate one species to give more room or light to another. As you become more interested in growing aquatic plants and become more experienced you can take on the trickier varieties and use more specialised equipment.

But the main thing is to have fun! And don’t worry. You will be able to grow something.