My goldfish are gardeners. They live in a 55 gallon drum that was cut in half and filled with hose water. It has a few overturned pots at the bottom of the barrel to give them somewhere to hide from raccoons at night. It has gravel at the base to provide a nice place to collect poop. It has a pump to filter the water. In the warmer months, a few aquatic plants float along the surface.
There are 3 goldfish in the barrel now. I feed them every morning. Once in awhile, I add another fish. Most of the time, I just ignore them. They ignore me too.
Every week, I scoop up a gallon or two of their water from the drain at the bottom of the barrel and use it to water my plants. The water is often fairly chunky. Bits of uneaten fish food drift by. Mostly, I’m looking for poop. This is free fertilizer.
Normally, fish fertilizer or emulsion is made from ground up fish. It’s rich in oils and nutrients that help plants grow. You can find rows of gallon jugs on garden shop shelves proclaiming the glories of properly fertilized plants. Ground up fish is good for plants. I’m not arguing this point.
I’m the Shoestring Herbalist. I don’t see any point in buying something I can make for free. We are what we eat. Poop is also what we eat. Fish excrete stuff that’s found in their bodies. Fish poop is chock full of plant friendly nutrition.
In the winter, my plants are fertilized primarily by fish barrel water. In the growing season, I supplement their diets with a comfrey based brew. Since my plants are healthy and happy, it seems to work. I like it because it’s cheap and easy. My plants like because it helps them flourish. My fish like it because … well, they don’t care. They’re still ignoring me.