Aquaponics Guide To Aquarium Plant Care

Aquaponics Guide To Aquarium Plant CareSetting Up The Aquarium In Brief

1. Place heating cable, Substore Mix and gravel into the aquarium as per instructions.

2. Place filter, heater thermostat and CO2 system in position but do not turn on until aquarium is filled with water.

3. Decorate the aquarium using bog wood, inert rocks or ceramic ornaments.

4. Fill the aquarium ¾ full of water. This will make the job of planting the aquarium so much easier and more comfortable. If the aquarium is to be left for a few days before planting do not turn the lights on until planted.

5. At least 80% of the substrate should be covered by the plants, with half of those being fast growing plants. This will help counteract algae problems which new aquariums are more prone to.

6. The aquarium can now be filled completely and all the systems checked to see that they are working properly.

 The Aquaponics System

This booklet sets out to explain how to grow aquatic plants in the aquarium. It covers their basic requirements, how we provide them, initial aquarium set-up (inc. planting) and sets out a proven maintenance schedule.

The basic requirements are as follows:

1. Light

2. Carbon

3. Other nutrients

4. Water quality


Light is a plant's main source of energy. It uses this energy to produce sugars and other compounds that fuel the plants other biological processes. It is therefore necessary to provide sufficient lighting for the plants maintenance and growth. However, whilst important, quantity is not the only factor. You may remember that white light is made up of the full range of colours of the rainbow from red through violet. Plants can only absorb (use) varying amounts of these colours. To ensure an optimal environment we must also provide different amounts.

The best lighting to use is special mercury vapour lamps or fluorescent tubes, from AQUAPONICS specifically designed to provide these optimal conditions.


Carbon is the main building-block of plants so it stands to reason that if they do not receive sufficient quantities of it they simply will not grow. This carbon is normally only taken up by the plants in the form of CO2.

In nature there is an endless supply of CO2 but in the aquarium there is often a deficiency which leads to poor growth or death of the plant. There are several reasons for this including: the removal of CO2 by the water authorities and displacement caused by too much water movement at the aquarium's surface or, even worse, the use of air bubbles for aeration. Any remaining CO2 will be used up rapidly by the plants and a deficiency arises.

The addition of CO2 to the aquarium not only benefits the plants but also the fish. Aquariums that lack sufficient CO2 often have problems with stunted plant growth, biogenic decalcification, and high pH values.

High pH values can lead to precipitation of iron, an increase in ammonia, or even diseases in fish. Ailing fish kept in AQUAPONICS systems with thriving plants will often recover without any treatment, because of the ideal conditions the plants help to create.

The addition of CO2 in the aquarium is now recognised as essential for a healthy and natural environment. The AQUAPONICS CO2 Starter Kit contains everything needed to supply CO2 to power-filtered aquarium: a disposable cylinder, regulator, CO2 tubing and diffuser.

CO2 Requirements Of An Aquarium

This depends on many factors such as intensity of lighting, water movement, whether the water is soft or hard, whether the tank is covered and how many plants there are. However, on average an aquarium of 100 litres will require between 1 and 1.5 grams per day.

Average life span of AQUAPONICS 450 g cylinder

Based on 1- 1.5 g per 100 litres per day.

Aquarium volume Life span

100 litres 300 - 450 days

150 litres 200 - 300 days

200 litres 150 - 225 days

250 litres 120 - 180 days

450 litres (100 gal.) 66 - 100 days

Testing For CO2

It is easy to test for CO2 using standard CO2 test kits but it is even easier to use a Long Term Test Kit for CO2. Simply place the 'activated' kit in the aquarium and compare the colour of the reagents with a stick on colour chart.

Other Nutrients

The remaining nutrients are taken up from the water surrounding the plant. For entirely submerged plants, this includes through the leaves and shoots. This is different to most terrestrial plants where the vast majority is only taken up by the roots. If you ever get the chance to visit a tropical stream, you will notice how for long distances, there will be a lack of plant life and then, a bit further downstream a sudden mass of growth. This phenomenon can easily be explained when we learn of the existence of nutrient springs. A nutrient spring is seepage of water from surrounding land containing all the essential macro and trace elements the plants require. Aquatic plants are only found in ponds and streams with these nutrient springs.

In the aquarium this nutrient spring seepage is simulated with the use of a Substrate heater cable and a special soil mix called Substore. Used together they provide:

(a) a nutritious substrate, as in nature, so important for plant growth and water balance;

(b) gentle convection currents, circulating nutrients between the aquarium and substrate;

(This also facilitates continual replenishment of the Substore by adding AQUAPONICS Aquatrace 7 to the aquarium water every seven days).

(c) a warmer substrate. If the substrate is too cold the plants become stunted;

(d) an environment within the substrate conducive to an oxygen-free zone. Remember, plants prefer rooting into anaerobic mud. Oxygen has the disadvantage of oxidising the nutrients our plants need and thus rendering them insoluble and useless, as the plants cannot absorb them. Any oxygen the plants require in the roots is obtained from the rest of the plant.

The substrate heater cable is placed on the tank bottom in zigzag loops. The warmth from the cable generates a gentle convection within the substrate circulating and exchanging the water within it every 24 hours. Because of the continuous gentle water movement, the substrate now becomes a biological filter and consumes all excess oxygen being pulled down into the substrate. Using the substrate cable and Substore, the plants will receive the best conditions we can provide and will thrive. Furthermore, given the natural properties of Substore coupled with the AQUAPONICS Substrate Heater Cable, fewer algae growth will occur.

Water Quality

Aquarium fish and plants, although mostly bred or propagated in captivity now, have their origins in the pools, streams and rivers of the tropics. These waters have properties that influence the biological processes of these fish and plants and as such it is prudent to try and emulate these properties in the aquarium. Most of the fish and plants we keep in the aquarium come from waters with a low mineral content or hardness and more often than not a corresponding low pH. Many aquatic plants are quite adaptable and can just cope with less than ideal conditions provided they are given sufficient CO2, nutrients and Trace elements, but fish on the other hand are more sensitive. It is for this reason we tend to use soft water with a pH value around 6.3 to 6.9. To achieve these conditions we can obtain our water from the following sources: rainwater, de-ioniser (DI) or reverse osmosis (RO).

Values To Aim For:

Carbonate hardness (°kH) 2-5

General / Total hardness (°GH) 5-8

pH 6.3- 6.9

Carbon Dioxide CO2 level 30 - 40 mg/l

To obtain the correct hardness levels some tap water may be mixed back with the DI / RO water or where tap water quality problems exist (i.e. nitrate / phosphate etc.) then hardness buffers should be used.

pH, Carbonate hardness and the CO2 level are intrinsically linked.

When either the Carbonate Hardness or CO2 level is changed then the pH will also.

A decrease in the Carbonate Hardness will in turn lead to a decrease in the pH and vice versa.

An increase in the CO2 will lead to a decrease in the pH and vice versa,

If the carbonate hardness is set at between 2 and 5 and the CO2 level at 35 mg/l then the pH will naturally stabilise between 6.3 and 6.9. This gives us an ideal starting point for establishing a harmonious environment for fish and plants.

Carbonate hardness, general hardness, pH and CO2 can all be tested using simple test kits from your aquarium store.

Nitrite And Nitrate In The Aquarium

Nitrate is frequently found in tap water and in high concentrations is harmful not only to fish but to the aquarium as a whole. Nitrate is a primary nutrient source for algae and a growth inhibitor. Nitrate can however be removed from tap water with Reverse Osmosis but any Nitrate that develops in the aquarium must be controlled by the aquarium system and by water changes.

Nitrate develops in the aquarium from the conversion and decomposition by bacteria of fish waste and other organic matter. This waste is converted to ammonium/ammonia, then nitrite and finally to nitrate by bacteria in the Substrate and biological filter.

This nitrate can be converted biologically by "reducing" bacteria into gaseous nitrogen with AQUAPONICS Denitrate. The production of nitrate can, however, be kept to a minimum in the mean time by plant growth under favourable conditions. These conditions are as already described in the section "Values to aim for."

When the pH is below 7, a higher percentage of ammonium is found in the water than ammonia, than would be found if the pH was above 7. Ammonium is not only intrinsically safe compared to ammonia, it is a much preferred nitrogen source over nitrate for aquarium plants.

Nitrite and Nitrate should be tested for once every 2-3 weeks, If the aquarium is kept at higher temperatures, is heavily crowded or meaty foods are used then the Nitrate should be tested more frequently. Ammonium/ammonia need not be tested for as long as the pH is below 7.

Planting The Aquarium

Aquarium plants which are bought potted should have the pots, Rockwool and foam removed before placing in the aquarium. This is very important.

The roots may be trimmed back to 1-2 cm removing broken and old roots. This will encourage new more vigorous growth and enable the plant to re-establish itself to the new environment.

Before planting it is a good idea to remove the oldest leaves especially if in a terrestrial form.

The rooted plants such as Echinodorus, Vallisneria and Cryptocoryne should be pushed deep into the gravel and then be pulled partially back up ensuring the crown of the plant is not covered. This procedure will gently straighten out the roots and promote fast root growth.

Small compact potted plants such as Lilaeopsis, Glossostigma and Echinodorus tennellus are still best planted individually although this is time consuming. This is best achieved using some long tweezers or thin planting stick. However, if this is not possible it is sufficient to remove most of the Rockwool from the bottom and plant the rest with the roots into the substrate.

Stem plants such as Cabomba, Hygrophila and Ludwigia, which are normally bought in bunches, should also have the foam and plant weights removed. Strip the lower leaves from the plant and push each individual stem into the gravel covering a few nodes. They are normally planted in groups and should be planted apart so that the leaves of each stem just touch their neighbours.

Once the aquarium is functioning normally and the plants are growing it will be necessary to trim and thin the plants periodically. The faster and taller growing stem plants such as Cabomba, Hygrophila and Ludwigia can be cut or trimmed in two ways. If just the head of the plant is removed leaving a node at the top of the beheaded stem then two new stems will grow from this point. This will lead to the thickening of the group above where the cut was made.

The second method is to remove the bottom section from the plant leaving a node at the base of the head, which can then be replanted. This head should be around 20cm length for best results. This will maintain the group of plants at the same size.

If we take this procedure a step further then even the middle of the plant can be used to produce new plants. The important point to remember is that any part of the plant used should have a node at either end of the stem.

Rooted plants with crowns such as Echinodorus, Vallisneria and Cryptocoryne should be kept in check by removing whole leaves including the stems from just above the crown. For plants with tightly packed strap like leaves such as Vallisneria it may be necessary to lift the plant from the aquarium and trim. The same may be the case for short lawn type plants such as E. tennellus and E. quadricostatus.

Establishing The Aquarium

New aquariums are always less stable, or out of balance when compared to well run-in aquariums. A sure way of minimising any problems including algae that may occur when running in the aquarium is to follow the Aquarium maintenance and start up schedule below.

Aquarium Maintenance And Start Up Schedule

% Water Change Conditioners Fertiliser Water treatments

Day 4 25% Biotap + Aquabio Aquatrace 7 Biotap + Bioextract

Day 7 25% Biotap + Aquabio Aquatrace 7 Biotap + Bioextract

Day 10 Aquabio + Aquatrace 7

Day 14 25% Biotap + Aquabio Aquatrace 7 Biotap + Bioextract

Day 21 Aquabio + Aquatrace 7

Day 28 25% Biotap + Aquabio Aquatrace 7 Biotap + Bioextract

Day 35 Aquatrace 7

Day 42 25% Biotap + Aquabio Aquatrace 7 Biotap + Bioextract

Day 49 Aquatrace 7

Continue 25% water changes at least every two weeks adding Aquatrace 7 each week. Use Biotap when using tap water in particular.

Use Bioextract to suppress algae and keep plant leaves clean and shiny.

In addition to this schedule a bacterial culture may be used to establish the biological filters more quickly, enabling the early introduction of fish without the fluctuating waste levels.

Fish And shrimp Stocking Schedule

First ensure plants have rooted and are producing oxygen.

Day 2-3 Introduce appropriate no. of algae eating fish or shrimp.
- 5-6 per 100 litres. Algae eating Shrimp are particularly good.

Day 10-14 Introduce 5-6 medium or 10-12 small fish for each 100 litres
- Feed only flake food very sparingly every 2-3 days at this stage

Day 21 More fish may be added each week until the aquarium is stocked
- Introduce 5--6 medium fish for each 100 litres as before.