Frequently Asked Questions

Aquaponics – Fish

What fish can I raise in an aquaponics system?

In aquaponics you can grow any fresh water fish that appeals to you. Considerations are that you want to be sure the environment your aquaponics fish are happiest in is one that your aquaponics system can naturally provide. Trout, for example, like water temperatures below 60 degrees. Can your environment consistently provide this? Also be sure that if you are mixing fish species that they have similar living requirements. Do they all prefer the same water temperature, eat the same food, and have the same oxygen requirements? Don’t mix carnivorous fish with herbivores, or you will find that you are just providing an expensive meal for your carnivores. We have found that tilapia, other cichlids such as oscars, pacu, goldfish, and koi all co-exist well together in an aquaponics system. See the post titled “Fish: To Eat or Not to Eat” in our blog for more detailed information.

How many fish can I grow in an aquaponics system?

A good rule of thumb is to stock about 1 lb of fish per 5 -10 gallons of water, or 1-2 fish per 10 gallons of water. Never stock more than 1 pound of fish for every three gallons of water.

Does an aquaponics sytem have an odor?

No, there is absolutely no odor at all.

Can I put fish in my system right away?

Yes.  See our post on Cycling With Fish for special considerations when doing this, however.

How much do I feed my aquaponics fish?

If you are cycling your system with fish, feeding should to be kept to an absolute minimum during the first 1-2 months. Only feed the fish what they will consume in 5 minutes – no more than 1 tablespoon per 20 fish per day. If fish don’t seem to be hungry don’t feed them. Fish can survive for weeks without feeding. Your water will probably go green for some weeks, don’t worry.

Once the water in your aquaponics system becomes clear you may gradually increase feeding levels, again paying attention to how much the fish consume in 5 minutes. You can also start feeding your fish twice a day.

What do I feed my aquaponics fish?

Depends on what type they are. We plan to offer fish feed for carnivorous (examples – trout and bass), omnivorous (examples – tilapia and catfish), and ornamental (examples – koi and goldfish) fish. Most fish also love Black Soldier Fly larvae, red worms, and garden waste (especially when covered with bugs!). See our Fish Feed offerings.

Where do I get the fish for my aquaponics system?

• Pet and Aquarium Stores: Just about any fresh water aquarium fish from a pet store works well in an aquaponics system. Pay special attention to the temperature range that the fish thrives in, and whether they would be compatible with the other fish in your tank (i.e. not eat them). Pet store fish we have grown with success in aquaponics so far are goldfish (avoid feeder goldfish, they are prone to disease), koi, oscars, pacu, and guppies.
• Hatcheries: More and more fish hatcheries are willing to sell small batches of fish to local aquaponic growers. You can also find online sources of shipped fish fingerlings, but this is becoming increasingly difficult as state fish and game departments are more tightly regulating interstate fish shipments. The Aquaponics Gardening Community keeps lists of sources for food fish fingerlings in the fish Groups pages.

What about fish diseases?

Fish in aquaponics systems tend to be unusually healthy and if your fish are introduced to your system disease-free they will most likely stay that way. Therefore, our best advice around fish disease is to purchase your fish from a reputable dealer (no feeder goldfish!), use a quality fish feed, keep the pH and water temperature where the fish are comfortable, and give them plenty of oxygen. If you have done all this and still think you have a fish disease then click on this excellent site for a guide to fish diseases for more information.