I'm considering embarking on my first foray into aquaponics. Actually this all started from a simple desire to have an indoor herb garden but I don't have a great place for natural lighting to set it up. So I was going to have to get lighting etc and so I thought why not play around with aquaponics. I saw some pretty nice aquaponic setups over regular 55-75 gallon fish tanks that won't have my wife yelling at me (too much). I was wondering if folks have had any experience with these kinds of setups and if they can be done "organically" and truly produce decent crop yield. The added benefit would just be a fish tank for the kids.
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.