There are two kinds of fish in our system at Hannah and Friends: goldfish and koi. Many of them we have had since we first built our greenhouse almost three years ago. These hardworking fish produce a lot of nitrogen for us, and koi and goldfish both tolerate a temperature range that extends from 55 to 85 degrees. That’s been quite favorable to us maintaining a greenhouse in a colder climate. In the winter we heat our aquaponic tank to a degree that allows us to grow vegetables that do well in cooler temperatures.
We always ensure that the fish get plenty of additional oxygen, which is important to maintain their health. Our fish were small when we first got them, but ever since we put them in the tank they’ve gotten bigger. Even one of the goldfish we had kept at home in an aquaponic system there never got very big until we placed in the bigger system at Hannah and Friends. It’s amazing what being in a bigger system can do to a fish’s growth! All of our fish have names, like Hulk Hogan, Nemo, and Tank that our friends have given them.
It’s really important with an aquaponic system to not overload the system’s capacity to hold fish. A good rule of thumb is to have one inch of fish per each gallon of water in your aquaponic system.
We make sure to feed the fish every day. We give them a couple handfuls of food and when we put it in the tank, our fish gobble it up pretty quickly. We’ve enjoyed learning about our fish, the things that make them grow best, and how to keep them healthy. Fish are quite social creatures and are very aware of their environment. They even know the sound of our voices. The closed loop between fish and plants in aquaponics makes a very powerful growing system indeed!