Backyard Aquaponics
A place to discuss aquaponics

G'day folks,

I have a metal water tank that I've taken the top third off of so that I can use the bottom 2/3 for my fish tank. Today I looked at the measurements again and found that this has given me a 8000lt tank!

To me this seems way too big.

I can take the middle piece off...thus giving me a 4000lt tank, which seems more appropriate. I'm also hoping, with some work, to be able to use the top third for a second fish tank at some stage down the track.

My concern is that if I break the tank down by taking off the middle section I'll most likely not be able to get it on again, at least I have doubts I would be able to.

Am I better off leaving it as it is, or making it smaller, or maybe even keeping it as it is and only half filling it?

I intend to start off with 100 Perch, then once everything's going ok adding 100 Barra.

I hope that makes sense!

Check ouy Jaymies tank. She's got around 10000L.

It's only too big when the surface area exceeds your local catchment area

like Jaymies tank

I would leave it be... but then again you need to decide now what is the biggest you would go then decide about what to do to your tank

I wouldn't add barra to a tank with silver perch. Chances are they will out grow the perch and snack on them along the way

too big? no such thing

Sheesh- thats a problem most ppl would like to have.
guess that means you could run several smaller tank series and
growbeds galore, with a big water body like that.

too big a tank a problem?

if you have the space to house the tank then i don't see the problem.

a larger volume of water will give your system more stability from water fluctuations, as well as reduce evaporation rate. the space will give your fish more room to move around, reducing stress and improving growth rate.

increase your stocking rate as you add more beds. this way you can gradually cycle the system, without stressing fish or plants. starting off with a large volume of water and a low stocking rate will be fairly forgiving.

i say go the 8000L. i wanna see it going.

I tend to follow the "can't be to big" camp.. But then I guess you must also keep in mind that if you have fairly low stocking densities in a large volume of water, then you may have to have larger pumps and more flow to pass enough water through the growbeds quicker so that the polants can get enough nutrients for good growth.

There was a thread early on where we began to discuss this subject, and it would be interesting to get back into it again. Just what stocking levels are required for some decent plant growth? And if you have lower stocking densities, does increased flow rate allow plants to have better access to the lower nutrient levels? So many questions, I've only raised more rather than giving answers....

I like the idea of a large stable water body feeding smaller growout ponds and GBs issolated by gate valves, and is the system I am working towards.
so I am interested in any comment.
C1 (about 70Kl)
I figure a large water body would have the same swings A, N, N, DO,pH and require same doctoring.

Howbout you just half fill it? Then if you want more you just top it up....

You can fill it incrementally. Start with 20 cm of water and a few fish and add more as your system cycles and you want to expand

Thanks for that people, I orginally thought the tank held 4500lt but on doing the calculations again was a little shocked to see just how much it does hold.

I thought Perch and Barra was ok in the same tank? Oh well....tis not a big one....will wait until I have the second tank up and running.

I think I'll stay with 100 Perch to start then throw another 100 in once everything is running ok.

Cheers

If the tanks big enough and you think 100 perch might feel lonely in that size tank....

Just stick your flippers on mate and go pay them a visit.... LOL

It's probably the only pool where you wont get thrown out for urinating ....

That will just go down real well when I have a dinner party!