Stocking density is a major consideration for anyone starting out in aquaponics. As so many people have asked about the best density for crop production, Dr. Nate Storey has given us an introduction to stocking density and some great advice that applies to starting, maintaining and managing a healthy and productive aquaponics system.
Aquaponics stocking density
Rules of Thumb for Stocking Density
Remember that every aquaponics system has variables that must be factored into your choices about the species of fish you select and the density you support. That said, here are a couple of general guidelines to help you estimate the stocking density for your system.
Lower density means fewer headaches
It is better to err on the side of lower density. You can adjust to the particular capacity of your system once you are comfortable with monitoring and regulating the water quality by adjusting how frequently you feed. Higher densities require more complex filtration and aeration setups. To keep things simple, stick with a lower stocking density.
A pound of fish, no more, no less
Plan for one pound of fish for every 8-10 gallons of water. This ratio is for the established system, which means you will need to base your initial figure on the approximate weight of full-grown fish. The adjusted ratio of fingerlings to add to the system after cycling works out to 1/10 of a pound of fingerlings per 8-10 gallons of water. When your fish are fully grown out you will have one pound per 8-10 gallons at system maturity.
When you sit down to plan it will save a lot of time and trouble to consider how you want your system to function and figure the stocking density accordingly. Don't forget that these guidelines are general.
This is a great place to start and it could even work as a rule, but be sure to pay close attention and test the water in your system frequently and consistently. Monitoring the system will help you to make adjustments to suit your production goals.