A basic Aquaponics system consists of a fish tank with fish, a grow bed with plants, and electricity that power a water pump. Also commonly used are air pumps and additional bio/mechanical filtration components. Aquaponics ecosystems must have the proper balance to maintain healthy fish and plants.
In an Aquaponics system, fish eat food and produce waste (mainly ammonia). Ammonia is hazardous to fish, even in small quantities (.04 mg/l) and toxicity increases in relation to pH and temperature. Ammonia (NH3) is food for beneficial bacteria (Nitrosomonas) which turns it into Nitrite (NO2) waste and then another type of beneficial bacteria (Nitrobacter) turns the nitrite into Nitrate (NO3) waste. Nitrate is less harmful to fish. The nitrate, phosphorous, and potassium are food for plants/algae which remove these from the water the fish live in. This is known as the “Nitrogen Cycle”. When the system is in balance, the water will be crystal clear and ammonia and nitrite levels will be zero.
Key elements of Aquaponics?
FISH. The fish are the driving force producing the nutrients in the form of ammonia and fecal matter. Their solid waste is collected in a filtration system and allowed to decay and release the nutrients. When you’re deciding what fish to use for your aquaponics system, you must take into consideration whether you’re raising the fish to be eaten or simply just to correlate with your plants. There is no ‘best’ fish. It depends on what is available to you, what is legal for you to keep in your location and what will live in your temperature range. Here are the lists of Fish recommended to work well in Aquaponics. Click Here.
PLANTS. The plants act as a natural filtration system, removing toxins from the water before it returns to the fish tanks. There have been over 300 different plants that have been tested that will grow in aquaponics systems including tomatoes, lettuces basil, peppers and more. Herbs and green leafy vegetables are the most common aquaponic plants grown in an aquaponics system. Different areas can also produce different results. Climate is another important factor as is whether your aquaponic system is open to the elements or in a green house.
NITRIFYING BACTERIA. It is the bacteria that convert the toxic components of the fish waste into a form of nutrients usable by the plants. Without the beneficial bacteria, an Aquaponic system will fail. There are two known bacteria that are responsible in oxidizing the ammonia and nitrite and they are called Nitorsomonas species and Nitorbacter species. Nitorsomonas convert ammonia into nitrite and Nitrobacter convert nitrite into nitrate which is the food for the plants. They will naturally exist when the system is properly cycled. These bacterial species have showed sensitivity to pH, with changes in pH affecting their ability to oxidize ammonia (Nitrosomonas) and nitrite (Nitrobacter).
RED WORM. Not only do worm’s introduce beneficial bacteria, funguses, grow hormones and enzymes into your aquaponics system but they also help to convert the solid fish wastes that would normally accumulate in your system into valuable nutrients and minerals that will in turn feed your plants. Worms can also be utilised to transport much needed potassium around your system. Worms hold a lot of nutrients and proteins in their bodies that help plants to grow, and they also prevent compaction and keep the soil fertile and in good condition.