Choosing Fish for Your Aquaponic System

When choosing fish for an aquaponic system it helps to look at the environment the system will operate in as well as what infrastructure (greenhouse, house, garage) will compensate for temperature fluctuations. Check out Tricia's video on Aquaponics where she tours an aquaponic system producing food in the middle of a cold winter! First and foremost the environment is going to dictate, to a large degree, the kinds of fish you are able to raise. Infrastructure, such as a greenhouse, will allow you to stretch your natural environment to some extent. Figure out what kind of water temperatures your aquaponics system will provide and match it to the types of fish that enjoy that environment. No sense in trying to grow trout in Arizona unless you are capable of providing for their needs.

Some key things to look for when selecting fish for an aquaponic system:

1. Capable of surviving within your temperature range for your location. 2. What is legal to keep in your area. 3. What is available to you. With these three things in mind here is a list of common fish used in aquaponic systems and their specific qualities:

Fish Maintenance:

- Feed fish 2 - 3 times a day but don't overfeed. This can be achieved by only feeding fish what they can eat in 5-10 minutes. Utilize a high quality organic pelleted fish food to ensure that the fish are receiving a well rounded diet, this will help prevent the fish from becoming sick or stressed. A healthy fish is the first line of defense to maintaining an aquaponic system. - It's best to observe fish during feeding and notice their nature. They won't eat if they are too cold, too hot or stressed. Monitor the the water quality and temperature to ensure that the fish are in the optimal conditions. Test water quality every other day for the first month, then about once a week or as needed. - A water heater will ensure that the fish are kept at the optimal growing temperature which will greatly influence the health and well being of the fish as well as influence their growth rate.

Fish Stocking Density:

- .25 pounds of fish per gallon (conservative) to .5 pounds of fish per gallon (moderate) - Essential to know what the harvest size of the fish will be to determine initial stocking density - What size tank will be utilized Example: Take for instance that fish harvest size will be 1.0 pounds and we have a 100 gallon tank. Tank size = 100 gallons Harvest size = 1.0 pounds First we take our 100 gallon tank and multiply by our conservative stocking density of .25 pounds for a total of 25 pounds. Total number of fish is then 25 pounds divide this by our harvest size which is 1.0 pounds for a total of 25 fish. Startup fish at 20% of total capacity (25 fish x 20%) = 5 fish. So for a 100 gallon tank 5 fish would be what to start with. Although the math may seem concrete this does not always transfer over to a living system. Always monitor the fish and get to know their habits. Selecting fish for an aquaponic system should be based on the habitat that you can provide for them, the fish that are available to you and as always don't forget to be sure to check local regulations regarding species of fish allowed.