Backyard Aquaponics
A place to discuss aquaponics

Quick update. The ich adventure is over. All my fish recovered nicely, and have not shown any signs of re-infestation after returning to their "pond".

I am still struggling with enough nutrients to the plants - slow growth and looking a little nitrogen starved. I'm adding some kelp solution, but after my experience with over-dosing before, I think I might be a little over cautious. Still feeling my way along.

I'm having trouble estimating how many goldfish I can keep in the pond since I don't know how much they'll weigh at maturity. Haven't seen the information around the forum (but haven't really searched yet) as to stocking rates for goldfish. Anyone have a suggestion?

In any case, the fish.

Goldfish are among the toughest fish, so you can stock them very high without too much trouble....unless they are inbred fancy goldfish like shubunkin, in which case I am not sure. I doubt they will grow larger than about 10cm to 15cm (100g?), so you could estimate based on that or call the pet store. I've seen goldfish that stop growing at 10cm and ones (in my greenhouse) that must be close to a kilo.

Last year I added NPK fertilizer to my system...too lazy to get up and look at type now, but was 16-16-16. I figured that I was running a sort of hybrid system in which the fish make a significant contribution. I will probably do it again this year when the trout come out, while waiting for the catfish to grow large enough to produce a decent amt of waste.

As I recall, UVI came up with the feed rates of 60g to 100g of food per day to support one square meter of plants. This may allow you to get some idea of where you are and where you want to be.

PS: I'm getting rid or trout right now in preparation for hot weather. If you would like any and happen to be in town, feel free to call.

Wow - nice clear water! Looks good!

I've seen koi and gold fish that are as big as some of my big catfish before. Some will grow as big as the space/food allow. Feed as much as they will eat a few times a day while keeping a close eye on the ammonia/nitrites to see if that will help.

Oh, wait, goldfish food often doesn't provide as much protein/nutrients as the commercial feeds meant to grow out big fish. Goldfish food is often meant to try and keep the nutrient levels in aquarium/ponds as low as possible while still keeping the fish alive. It might improve things for you plants if you can get your hands on some dence culture feed of some sort. In the mean time perhaps some very small doses of the fish emulsion might be ok but make sure they are small doses (talking like a teaspoon added at the inlet to a grow bed) and that you keep a very close eye on the ammonia/nitrite levels as you do it since it is effectively putting ground up fish into the system to be broken down so it would be easy to over load the bio-filters.

Good Luck with it the first season is often hard, just take heart that it will get better.