Backyard Aquaponics
A place to discuss aquaponics

I just set up a small quarantine system. It has a half barrel grow bed attached for biofilter and 25-30 gallons usable tank capacity. (keeping the level fluctuations above the 25-30 gallons that is.)

The system is jump started with water from the main system and a good sampling of gravel that was pre-started in the other systems. I will do a little fishless cycling but I don't expect it to take muich.

I am wondering how many fish I dare keep in such a system for 3 weeks? I am hoping to get some tilapia soon. I intend to plant some salt tolerant plants into this system and keep it salted.

If they are say 50-100 mm, how many fish could handle being in 27 gallons of water for 3 weeks?

Lot's of air ,, decent filtration ,, 500.

I am not sure I would go with that many. That would be about twenty fish per gallon. At that size with plenty of air and frequent cycling of the water, close monitoring, I would figure no more than 5-8 per gallon for that length of time. Remember if things go well, they should be growing during that time.

That means 100 fingerlings should be fine in 25-30 gallons for a few weeks.

That's good.

My opinion

No more than 0.5 lbs per gallon as final harvest density.

Start with no more than 0.25 lbs per gallon should be a comfortable level regardless of size of fish. If less than better.

AERATE!

The tilapia fingerlings could double in size in a few weeks so growth should be accounted for.

Are you going with all males? or natural (mixed sex) ?

The males will grow faster. But if you put the mixed sex with the catfish, the catfish will keep some reproduction in check (not all).

The catfish are in a separate tank than where I'm planning to put the tilapia.

I wasn't sure if I would go with the mixed sex or the all male. It might be worth it to get all male this first round.

I would happily put 100 in

All male system is used by nearly every successfull grower I have ever met.

Just an update.
When I got my fish, I got 100 (at least I paid for 100, I do believe there were a couple extra plus some itty bitty ones made it in too) mixed sex fish mostly between 1 a and 3 inches in length. I also got three larger sexed fish (two female and one male) to have as breeders.

Originally they all went into the single Quarantine tank. Problem is that system I had only just set up a few days before so it wasn't cycled yet. I've been having to do some water changes as a result and haven't been able to feed the fingerlings as much as they would like.

So as a result of my experiences here, I do believe this tank is plenty big enough to house 100 small fingerlings for three weeks easy if the system were cycled.

Some other things I learned from my experience. Another place for the large breeders is needed, perhaps 3 separate places or one tank divided as I lost one of my breeder females due to fish violence.

I have a barrel ponics system (in use as pee ponics) but It got pressed into service as a quarantine tank for the breeders. Unfortunately, that is where the violence happened. A blue barrel fish tank isn't very easy to see into it seems and I fear the tragedy may not have happened if it were easier to see what was going on and catch that there were injuries before it went too far. Anyway, in the future, I suppose the barrel system could be used as a Quarantine system but I would definitely not use it for the bigger fish and since it is so hard to see in, I probably won't use it unless really pressed for tank space.

So what is going on now. The two remaining breeders are in my bigger Aquarium with a handy divider to put between them when I'm not checking on them hourly. That system got a better jump start on cycling I hope with a couple bags of shell that had been sitting in the catfish tank.

I only lost two of the fingerlings early on. Some sort of weird patchy looking skin , everyone else seems healthy. Weather has been very warm lately so tomorrow the fish will move to the big cage within the big tank. Three of the larger ones went in the cage today just to test the water for the rest of em.

TC ,, I actually prescribe , medication. If your checking fish ever hour and building things like you are ,, I recon your manic,..... NO OFFENSE meant ,, I am bi-polar ,, what ever the fF that "means.I would stay up most of the night designing the better ....., bowling ball +,house, farm , fish ,, frog, car,, television shoe ,,,WHATEVER
It is not just your body that needs sleep .
Speaking of which ,, I now need to rest .
God bless you all.
Dave

Not manic,
perhaps autistic but that's a whole other story.