Have you looked at the ingredients on the fish food at the big box pet stores?
I’m guessing you’re here because you want to feed your fish non-GMO goldfish food. You don’t want that stuff going into your system when you plan on eating the food from it. Here’s what you can feed your goldfish that is free of GMO corn, wheat, and other nasty ingredients. I tell you how to make sinking or floating food. I cannot guarantee feeding other types of fish these things will work, but my goldfish like to eat healthy, and it’s fun to experiment. Sign up for an email course of all my aquaponics videos here.
Goldfish are good to start with if you’re new to aquaponics.
They typically eat from the top of the water, so they are good at mosquito control as well. I personally use mosquito dunks in my system, as mine is outdoors. I don’t like it, but these dunks use organic approved BT to prevent larva from forming. I don’t eat BT corn, but at least this BT is simply in the water, and not input into the genetics of my plants. BT is a naturally occurring bacteria, that I am increasing to prevent the mosquitoes that can cause multiple diseases. It’s worth it in this case. If you have an indoor system, you may think you don’t need it, but consider this:
Once they start breeding, the only thing that will kill them is a pesticide. The dunks will only prevent larva and so that alone will take weeks to take effect once you already have an infestation. And imagine an infestation in your garage or basement! That would be way worse than in your yard. I am against herbicides, pesticides, and GMO’s, but in the case of organic grower approved BT, I am fully for it. Especially once all of the risks are weighed out.