Backyard Aquaponics
A place to discuss aquaponics

Can one of you with tilapia experience offer some guidance on how fast fry grow? Our system is "under construction" but I want to get things moving as quickly as possible so we can harvest fish by next December. How long do you suppose 100 fry (of the size that would be air shipped) could live in a 50 gallon aquarium before they'd outgrow it? I'm wondering if I can buy some more time by growing them indoors in a conventional aquarium for a few weeks (longer?) while the AP system gets finalized and cycles with some goldies. What do you think?

I have a little experience. -- it seems that tilapia grow in proportion to how much they are fed. I have some fry that hatched about 3 weeks ago -- now they are about an inch long. (2.5cm)

I've got over 100 in a 20 gallon aquarium.

But I'm thinking I need to move some into larger quarters. I understand that fish that are too crowded/underfed/nitrite poisoned can become stunted for life.

If your aquarium has a good filter that has already been cycled, it might not be a bad idea. Otherwise, you could set up a miniature growbed inside -- or at least a gravel filter with a pump -- that would be more effective at removing ammonia and nitrites than most aquarium filters -- and start your bacterial culture for your growbeds.

And in my opinion, forget cycling with goldfish -- just toss half a dozen or more tilapia into your real system. -- if it isn't finsihed yet but you have a tank, pump, and at least one growbed that can drain into the tank, put all the Tilapia in there and get that growbed started. Then you can save a dozen or two to keep inside for insurance. By the time they're 2" long or a couple of months old, they'll be ready to breed.

Little Froggi, that's already twice as many fish as I would put in a 50gal with standard filtration.

The aquarium rule of thumb is 1 inch of fish per gallon. They ship the fish at about one inch long. This rule works pretty well for smaller fish, but because of the mass of larger fish, it breaks down after about 4" long.

If you want to drop extra filtration in, you might get yourself a month, but remember that DO is a factor, too.

I currently have over 250 Red Mossambicus of about 120g each in a 2900L tank (total water in the system about 8000L) They handle everything thrown at them except low DO. I feed lightly, aerate heavily. These are expected to grow to 400 + grams each (all males). I am also way under spec on my grow beds. I am not implying that you can throw away the rule book with Tilapia, but the rules can certainly be stretched somewhat with these hardy little critters.

pretty fish. Maybe someday I can get some.

Mossambicus! I have some of those. Now I just have to figure out which are females so I can breed them to the hornorum. Your fish have a better red color than mine. My pretty babies are more orange.

How hard is it to use hormones to make all your fish male? Is that something we could do? Right now I'm betting on genetics of two strains to produce mostly male offspring. Its kind of a pain. I still dont know how tell which are male and which are female.

DDM, the the Males are one that display the most impressive colours. All my female tilapia are a fairly boring silver colour. The three males are almost jet black, with red and yellow on their fins.

As soon as I disturb them they fade back to silver.

The reason they are so colourfull in the picture above is because they are all males. By putting only males into a tank, they focus more on growing and less on breeding.

DDman, do you have access to hornorum?
If you do, we'll have to find a way of getting some eggs shipped here by mail, there's no way we can get some in Europe.
I've tried a few different country retailers on the net and it is not possible to have them.

I was talking another person this thread who needs them also. It looks like I will get to try shipping eggs packed in butter with a little "Lift OX" slow release oxygen dropped in. The question is can you get a package in 10 day from here and can you incubate them?

I am also looking at trying to build an incubator. I am thinking about using a funnel with a gentle upward flow of water to push the eggs up and they will roll down the side of the funnel. Then use a UV light with a sand filter and a cartridge filter. I hope it will work.

If I breed the hornorum together then they will be a little inbread. The person who sold them to me might even ship the eggs to you directly, I dont know. Its such a touchy subject; if you know what I mean.

Hey Janet Who was the guy on ebay selling hornorum?

Was it BardPaper ?

What is 'hornorum'?

Hornorum tilapia are a silver fish. When the male breeds a tilapia mossambica then you get 99% male offspring. Which is what you want for food because they grow faster than females and in a culture of only male fish they do not wasted energy mating, they just grow into plate sized fillets.

See http://www.pisces-aqua.co.uk/aquatext/i ... rnorum.htm

and
http://www.pisces-aqua.co.uk/aquatext/i ... sambic.htm

I'm sure we could get a parcel here fater than 10 days.
I had some rainbow fish eggs arrive in 5 from australia which is a bit further.
Did you check the tilapia for us thread, i had posted a document which was giving the best solution for tilapia incubators.
In resume, they were saying that a round bottom tube with a nice slow flow gently moving the eggs and overflowing on top is the best.
Like a lab tube with a pipe like a dripping system going in it seems the best.
I had seen another solution on a farm, it was a fine sieve like the ones for sand with a water flow going upward and lifting the eggs from the mesh.

I did read that. Thanks! I just could not see how that would turn the eggs. Simple is good though. Is it hard to strip fish of eggs and sperm?

Don't need to do that with tilapia, just take the female after a two or three days and gently press on the operculum in a bucket. She will spit them out. needs a few gos to get the technique but it is very easy.
The most difficult trick is to catch the female to do it!!
A friend of mine who does it with African lake cichlids catches them at night, after two hours of dark they are usually easy to catch with a torh lamp.
Check the cichlid sites to find more details on cichlid egg stripping.
The eggs turn on the round bottom just the current of water.