Fish Selection for Aquaponics

We've written extensively about the aquaponics setup at Better Farm—from the budget to the science behind it to the crops we're growing. But one of the biggest (if not the biggest) components to a healthy aquaponics setup is your selection of fish. So today we're going beneath the surface to check in with our fishy friends.

Photo/Aaron Youngs

Photo/Aaron Youngs

The fish and plants you select for your aquaponic system should have similar needs as far as temperature and pH. There will always be some compromise to the needs of the fish and plants but, the closer they match, the more success you will have.

As a general rule, warm, fresh water, fish and leafy crops such as lettuce and herbs will do the best; as will your dirtiest, most durable fish (our opinion: goldfish and minnows). In a system heavily stocked with fish, you may have luck with fruiting plants such as tomatoes and peppers.

Fish regularly raised in aquaponics with good results (please note: all "edible" fish should be raised in a tank that holds at least 40 gallons of water):

• tilapia
• large mouth bass
• sunfish
• crappie
• koi
• fancy goldfish
• pacu
• various ornamental fish such as angelfish, guppies, tetras, swordfish, mollies

Other fish raised in aquaponics:

• blue gill/breem
• carp
• barramundi
• silver perch, golden perch
• yellow perch
• Tilapia
• Catfish
• Large mouth Bass

Plants that will do well in any aquaponic system:

• any leafy lettuce
• pak choi
• spinach
• arugula
• basil
• mint
• watercress
• chives
• most common house plants

Plants that have higher nutritional demands and will only do well in a heavily stocked, well established aquaponic system:

• tomatoes
• peppers
• cucumbers
• beans
• peas
• squash

At Better Farm, we wanted fish that could withstand cooler water temperatures, fish that exhibited hardiness  (longevity), and fish that would maintain a good nitrogen level for plants—all without breaking the bank. We settled on a bunch of "feeder fish" (minnows and goldfish), which were extremely inexpensive. We also picked up two koi (we bought the smallest/cheapest, which have now quadrupled in size and appetite) and a few "hand-me-down" fish (tetras, a sucker fish, and a carnival prize from two summers ago).

Because we have a 70-gallon tank, there's space to experiment with tillapia or other trout; so long as we account for the space needed by mature fish (roughly one gallon per inch of fish). Our ratio of fish-to-water-to-plants has worked swimmingly so far; stay tuned as we expand and experiment with new setups, more setups, and different fish.