posted 5 years ago
My setup is organic. (I did use osmocote and miracle grow last year, but this year I haven't used any.) I haven't had any great yields, but more things grow each year, and things also grow better each year. I assume that's because organic matter is increasing, and because the growing media has active bacteria (and maybe fungi) colonization. I'm sure the soil life is not the same as good garden soil, but maybe some of the same players are at work?
My media is sand. I try to leave roots in place, encourage legumes, mulch with any weeds I pull, and bury any fish that die. Last summer, I mulched about an inch deep with grass clippings, once. I flood and drain, by having my pump on a timer. It runs for ½ an hour, either 4 times or 6 times in 24 hours. (I forget.)
I suspect improvement would be quicker if I stocked my fish more densely.
A person willing to spend more than me could use organic (foliar feed) fertilizer. You might want to check out Jack Spirko's Survival Podcast for that sort of recomendation. I think he likes Garret Juice, Dr Earth, and a couple products I forget the name of for minerals. He gets better growth the first season than I'm getting now, but he spends more money to get there.