Aquaponics - Fishplant Systems

What is the FishPlant system?

The FishPlant systems have been developed in conjunction with Aquaponics UK at Stirling University.

The FishPlant Family Unit is an aquaponic system. The combination of aquaculture and hydroponics. You can raise fish and grow plants in an enclosed eco-system with beneficial microbes providing the bridge that converts the fish waste to usable plant nutrients. When we feed the fish, we are also feeding the bacteria and the plants. In relation to a natural eco-system, the FishPlant is small and simple, so we must help to maintain the correct balance.

The FishPlant Family Unit is a great way to get started with aquaponics; large enough to provide a couple, or small family with plenty of fresh salad, and stocking up to 3.5kg of fish. Yet small enough to fit into a small garden, greenhouse or even indoors. Compact and easy to use, it is also ideal as a nursery system or a module in a larger setup. The low height of the system makes it very accessible and easy to use.

The package includes everything necessary to setup the system including the clay pebbles. Full instructions and operation guide are included; no tools are required for assembly. Because of the compact design the fish tank and grow bed can be manoeuvred through normal doorways. The FishPlant Family unit operates on a flood and drain system with an autosyphon which provides efficient, low maintenance operation.

 

How the FishPlant system works

The PlantBed of the FishPlant system is based on the ‘Flood & Drain’ (or ‘Ebb & Flow’) hydroponic technique – the ‘Flood’ bringing water and nutrients to the plants roots, the ‘Drain’ drawing fresh air (oxygen) into the root-zone.

The water pump runs constantly and the AutoSiphon controls the flooding and draining. The AutoSiphon cycle starts when the water level in the PlantBed passes the overflow point of the Downspout and starts to siphon back into the FishTank – this also helps oxygenate the water for the fish. The siphon will flow faster than the inlet flow rate and will drain the PlantBed until the water level reaches the siphon break point. Then it will start flooding again (see diagram).

 

Do I Need Extra Water Circulation?

The Flow Fitting also directs some of the pumped water directly back into your FishTank which ensures constant circulation and helps oxygenate the water for the fish. If you add beds or nursery tanks to your system, at a later date, a second circulation pump may be required then.

Do I Need Extra Aeration?

High oxygen levels in the water are important for healthy fish so you may wish to consider a FishPlant Air-pump and FishPlant Air-stone for your System. We strongly recommend this for heated systems as warm water naturally holds less oxygen.

Do I Need A Heater?

This depends on the fish species you plan to keep and the environment your system is in, for Tilapia you will certainly need one (require 24-32°C), such as the FishPlant 300w Heater.

 

Sourcing your fish

The first decision you have to make is what fish to grow. This depends on whether you intend to eat them or just keep them for pleasure. While the principle of aquaponics is primarily to grow food, it may be that you prefer to grow ornamental fish such as Koi Carp or Goldfish and just eat the plant produce. If this is the case you are likely to use lower fish densities (hence feed less) and therefore the amount of plants it is possible to grow will be reduced.

If you are planning to eat your fish, there are a number of species to choose from such as carp (common or mirror) and perch to name just a couple, but the one we strongly recommend, certainly if you are new to fish-keeping and/or aquaponics is Nile Tilapia (Oreochromis niloticus). It is a tasty fish, that is hardy and tolerant, which can be kept at a high density and is resistant to disease. With the right conditions they can easily be grown to harvest size in six months.

Fish should always be sourced from a reliable and reputable supplier, if in doubt, ask to see any paper work related to where the fish stock came from. Generally speaking, fish that have been bought for ornamental purposes should not be eaten as they may have been treated with harmful additives. When buying fish that are held in a tank avoid those that are being kept with sick fish or those that look stressed. When transporting your fish back to your fish plant system, try to keep stress to an absolute minimum.