In the very beginning, I advocate the use of a seaweed extract such as Seasol as an initial boost for a new system. It gives the new system something to work on and acts as a tonic for the new system aiding in the establishment of the beneficial bacteria..
A new Aquaponics system needs time to develop all the bacteria and microbes that will convert and release the necessary nutrients for good plant growth.

Aquaponics systems closely mimic nature in the way they handle and provide nutrients for the plants. Eventually there is a myriad of bacteria and other microbes that do their job, just as they should in a mature Aquaponics system.
The job of the two main beneficial bacteria in converting the ammonia produced by the fish to nitrates is very obvious. They are established in a new Aquaponics system usually within a few weeks. It takes time for all the other natural processes to develop and establish.

This is the amazing thing about Aquaponics . The way it becomes so balanced and complete.

I also advocate a once or twice application of Mineral Rock Fertiliser. This is done to help “kick start’ the mineral and trace element build up in your new system.
The Mineral fertiliser supplied by us with your kit is mined by ALROC and is an excellent natural rock extract. See mineral analysis data for ALROC No. 1 providing nutrients to the plants.ix. Link
It should be applied at the rate of a quarter of a cup sprinkled over on grow bed. Natural organic mineral supplements work slowly and are not like chemically derived fertilisers.

ALROC Mineral Rock fertiliser can be applied once every 6 months to assist in a balanced mineral load in the system. Personally I do not add it again after the first year. I have not observed the need to do so.

If you have Clay Pebbles as your grow bed media, by hand, work the Mineral fertiliser down into the clay pebbles just below the surface where it will be broken down and absorbed by the water.
If you have regular gravel it is easier just to sprinkle on the top of the gravel and water in using a watering can. You may have to water it in several times until it is broken down and soaks into the gravel bed. It should be noted that it is a natural function for soil based microbes and bacteria to release minerals from natural materials such as soil, fish waste solids.

You may find it a good idea to add a half a teaspoon of Chelated Iron to one of the grow beds once a month. Iron deficiency is often encountered in new systems. This is most often a symptom of “Nutrient Lock Out” caused by pH above 7. As pH stays above 7 nutrients are locked up and are not available to the plants even though they may actually be in the system.

Aquaponics systems run best at pH 6 to 6.8.

If adding Iron, just use a little water to wash the Iron down in amongst the grow bed media. The Chelated iron can also be added straight down into the water beside the auto siphon device.
This way the iron will be dispersed more slowly around the bed/s. Even though it is added to just one bed, it will find its way around through the entire system.

Potassium and Calcium are also needed in Aquaponics systems. If feeding your fish on commercially available pellets these two elements are often in short supply in your aquaponics system.

These two elements are easily supplied as part of pH control / adjustment.

Practical Aquaponics.

.We decided to try aquaponics because these systems are extremely water efficient. Since the water is constantly cycled between the fish and the plants, the system uses much less water than growing vegetables in our dirt garden.

This system has six 200-litre grow beds with vegetables and two 450-litre fish tanks, each containing 20 silver perch fingerlings. The water is pumped from a sump to the fish tanks, then the water gravity feeds down to the grow beds, and from there back to the sump. Animation showing the way the system operates can be found at http://www.aquaponics.net.au/Chops.html.
You can also see a video of the system at YouTube - http://www.youtube.com/watch?v=_Qc5VF7k3IQ.

A small solar panel runs the pond pump (4000 lph) and aerator on sunny days. Tank water collected from the roof of the shed is used to replace water lost by evaporation and transpiration. The fish are fed on composting worms and commercial pellets. I have four worm farms now, and hope to feed the fish mostly on worms soon. Since the grow beds are located above the ground, weeds and pests are easily managed organically by hand. The bottom half of the beds are filled with 20 mm gravel, and the top half with expanded clay pellets.

To protect against heavy rain, hail and wind, we have constructed a shelter covered in clear Perspex, with roll down shade cloth.

So far we have successfully grown tomatoes, beans, Lebanese cucumbers, beetroot (beets), silver beet (Swiss chard), rock melon (cantaloupe), basil, chives, coriander, parsley, lettuce, snow peas and strawberries.

Very entertaining and rewarding!
JULIA from Cooroy Qld.