Backyard Aquaponics
A place to discuss aquaponics

I have recently set up a small system (20 gallon FT, flood and drain growbed) and was doing some reading about goldfish stocking densities.

From what I've read on "goldfish" aquarium sites is that the first "common" (ie not fancy) goldfish should take up 20-30 (slightly conflicting here) gallons and another 10 gallons for each additional fish.

However these guildlines are for typical aquarium stocking and not aquaponics. I wanted to start with 3 of the small comet goldfish from the store (17 cents each at petco) and then give it some time to see what happens to the biofilter and how it handles it.

Is this too much fish? I plan on growing basil (cuttings planted yesterday), chives, and maybe rosemary.

Its also important to note I do plan on expending my system around 6 months of running time by adding a larger tank, so I'm more worried about the bioload of the fish than their grown size.

depends how big ur growbed is

i think u will be fine but they grow pretty quickly- and if the plants die/get harvested you could run into trouble

20g is like 75L? perhaps start with 2 goldfish need space to swim even if the filtration can handle it

Yeah its about 75L, I just added a small volume expansion via a trash can and bridge siphon. I figured while it doesn't give the fish a place to swim it does increase the volume of water to make it slightly harder for conditions to rapidly change.

I guess I'll just start with 2 of the comet goldfish and see how things go.

Grow bed is about 40L, new expansion is 20L water, some left over river rock from my bed being about 4L thrown on the bottom.