Aquaponics in Winter
As the water temperature drops, so do many fishes' appetites within aquaponic systems. The major concern in aquaponics in winter is overfeeding, as uneaten food releases ammonia and reduces oxygen. If the fish have not eaten all of their food within an hour it is best to scoop out the uneaten feed. Colder temperatures are also dangerous for some types of fingerlings. It is best to keep the water above 16°C for Jade Perch and 12°C for Silver Perch, however they will not die until the temperature is below 10°C.
Raising the temperature
To raise the temperature and promote faster fish growth, water heaters such as the Aqua One Heater, can be added to the fish tank together with thermal insulation. Because the majority of the heat will be lost from the water's surface, having a lid fitted to the top of the tank can also reduce this heat loss. Attaching insulation batts or styrofoam to the sides of the tank can also help insulation the water. If you are going to install your system on a concrete surface, we recommend a layer of Styrofoam between the fish tank and the concrete to help insulate the water from the colder concrete.
Not enough food for plants
Aquaponics in winter leads to reduced appetites and then fewer nutrients enter an aquaponics system. It is best to reduce plantings in the cooler times or consider adding more fish. If neither is practical, some supplements can be added to increase nutrients such as nitrogen etc. A simple test, such as the API Nitrate Test Kit, can measure how much nitrogen is available to plants.