Fish care

Type of fish

Red Tilapia is best for the unit startup. They are hardy and tolerate swings in the conditions of the system better than most. However, below is a list of other types of fish used and their best operation conditions.

It would be best to choose your fish for your area, especially for temperature or the water. Also, select the fish according to your market price and requirements.

We suggest Tilapia or Jade Perch. Barramundi is also good aquaponics fish.

Maintenance

Clean the fish tanks the solid separation tank, and the biotreatment tank daily. Wipe the algae out regularly. 
Deep clean the solid separation tank monthly. 

Fish mortality

We observe 5 to 10% mortality over the 6-month lifetime of the tilapia fish. It is, therefore, acceptable to see one dead fish per tank every 2 to 4 days. Any mortality above this average, or increasing mortality, should be investigated.

Fish feeding and fish food

Fish feeding is probably where the operator’s feeling and observation are most required.
Since each tank hosts a specific fish size and differs from its neighbor tanks, each tank requires a different quantity of fish food.

Nevertheless, the number of plants drives the system's food input requirement. Count 30g per blue board full of plants. So, to maintain proper plant growth.

Once the system is mature, the Nitrate content drives this quantity of fish food. Feed daily to maintain nitrate between 100mg/l and 200mg/l for a vegetative system. The process is more complex for reproductive systems, and AHAS can assist through coaching sessions.

The best feeding technique starts with the quantity we expect the fish to eat. This quantity should be eaten in less than five minutes. Then, observe the fish's behavior and add more food if they still look hungry. 80% of the total quantity is the baseline expectation for the next day.

Spread the fish food into three feeding sessions. Feed at the same time every day. Feeding the fish should be done at regular times. This way, you can see how the fish react to their food and how healthy they are. Morning lunch and dinner is good for us and also suitable for them.

Ensure that all the food is consumed and not left to become debris in your MIT.

Fish food should be of good quality, with a minimum of 32% protein, organic, and with probiotics if possible.

We recommend 30g per blue board. The unit runs on 2.4kg of fish food per day. But this depends on the actual plant selection you are growing. Fish food is adjusted based on Nitrate content. Maintain nitrate at 100mg/l to 200mg/l level. Should nitrate increase over 180mg/l, then fish food can be reduced. Hanna Instrument provides great nitrate testers. 

The Nitrification process

The nitrification process converts Ammonia (NH3) into Nitrite (NO2) and then Nitrates (NO3).
It requires two types of bacteria:
- Nitrosomonas: Oxidizes ammonia (NH3) into nitrite (NO2). Ammonia and Nitrite are harmful to fish.
- Nitrobacter or Nitrospira: Oxidizing nitrite into nitrate (NO3). Nitrates are harmless to fish and are absorbed by the plants