Backyard Aquaponics
A place to discuss aquaponics

So how many fish do you think are needed in a new 1000L IBC system to produce this growth...

14/02/12 ... Transplants & Seeds ...

06/03/12 ... things smashed a bit by rain...

So that's 21 days... from start to now...

Assuming system was already cycled to begin with?

Nope...

10

Trick question 0: you peed in it.

p.s. keep the mystery going for awhile!

How big are the fish? Are they fully grown already or are they fingerling size?

0 - 10 with the occasional addition of seasol.

Good to see you have gotten a new system set back up. Hope the rain doesn't keep crushing things too much.

Yeah, the rain hasn't helped things...

So is this feeding the fish only without adding anything else at all?

Basically... for the first two weeks... there were NO fish in the system.... in the last week photoed... there had been TEN fish added....

The first poll response was 30-40 fish... most other people, knowing I tend to lightly stock went for 10-20... The poll has been skewed a little, by people reading other threads.... and picking 0-10...

Ok... here's what was done...

3 x palmfuls of urea... and 3 x gulps of Seasol/Maxicrop... spread over the first 2 weeks....

The media in the grow beds had been previously used... but was washed.... and the system water was seeded from another system...

And I am cheating a little... most plants were seedlings... and the NFT tables are commercial hydro seedling plugs...

And the fish were... well not fingerlings... Silver Perch... ranging from 800-1200 grams... biomass about 10kg/1000m3...




But the photos show the growth...

The point is.... you just don't need a lot of fish to produce a lot of veges... certainly nowhere near the crazy densities advocated on other forums...

And, indeed... not even close to the 40-60 fish that 2 x 500L grow beds could theoretically support... assuming a 500gm harvest... a max of 25-30kg/1000m3...

This module will probably be bumped to 20kg/1000m3... as I've added the third NFT...

But another module with only two NFT tables, and 10kg/1000m3... will go up shortly...

There just is no need to stock anywhere near what people do... if the veges are what you want... and that's also shown in the BYAP trials....

But... if you want to stock for the fish.... then you're either going to need some external filtration... or twice-four times the number/volume of grow beds....

The 1:1 ratio that has become almost universal... as opposed to the "old" 2:1 ration... is bordering on the brink of disaster IMO... if you don't eat your fish regularly at, or under 400-500gms...

And doubling the stocking density.. while maintaining a 1:1 ratio... is just plain stupid IMO...

Especially if you're feeding your fish to the max... as is often the case when running trout...