Backyard Aquaponics
A place to discuss aquaponics

here it is

800 fish, wow!

In fact it is possible to have the control on the predation in a tank, it is done for a few very difficult species.
I've seen it work for breeding in ponds and having enough fry from the small specie to produce exactly enough fry to feed the primary specie and not have a predator impact that is to big from the seconds on the fry of the first. All is based on the daily feeding basis of each of the species added with the reproduction rate, this gives you a total number of each fish to introduce. It has been done by the chinese for millenaires and they are the best fish farmers ever by the fish output quantities.

And don't forget that mother nature always selects the best fish for the system, the important is the genes that you introduce primarily with the brood stock. The species adapt to their new environnement and usually the ones who survive are the bigger ones and the ones with the fastest growth rate.
The thing is to control the hole system and help it a bit sometimes when it needs, by reducing the fish density per example

The last is to think of a predator fish that you can eat, better than piranha at the taste, if you stay in the idea of separating the prey and predator.

I believe ' same-tank ' predation would work wonderfully, in large commercial type set ups. A small system needs more human intervention to keep things in check.

The main trait in fish i am looking for is a solid body colour, the fish have a tendency to turn blotted after few generations, i want a nice solid red, nature wants fish that can camouflage but red sells better, ' separate-tank ' predation is how i am going to help nature, .

Piranha eats their own as well so no nutes lost their either.

I am looking at all the options out there.

I'm sure you've all heard that tilapia are considered a pest in many areas. Our local paper has had 3 articles on them this week. This was the first.

I found that separating the fish did not necesarilly accomplish bigger growout rates for the males, although it was fun keeping them apart and then reintroducing them in breeding tanks where they mated rapidly, the truly limiting factor in AP growout is

1) the amount of biofilter (and plant respiration) available to filter the fish emulsion
2) dissovled oxygen levels
3) and ultimately the frequency and duration of feedings.

The more fish respirate and consume nutrients, the bigger they get. It is very simple. But in an AP system it can be hard to get plant respiration to pace or outpace fish respiration, so you are bound to the amount of biomass you can cycle. The greater the mass, the greater size of the fish....

Regardless of the species, I do not believe the hype of the hybrids. And as far as dosing fish with hormones, well that is a rsik I would not take in terms of eating the fish.

All good points michael. I am just about ready to throw them all together and see what happens. The main thing is that I get 40 baby that survive each month.

I have made some observations about Hornorum in relation to mossambica.

-They have more personality
-They are more alert and curious; watching and following you.
-They are less shy, even eating from your fingers.
-They grow faster than mossambica.
-They are larger
-They have a bigger appetite
-They spend less time chasing each other around the tank; calm fish
-They dot run from the smaller aggressive male mossambica
-Their body shape seems like they would make better fillets.
-They have the ability to train spouses to over feed them.

I am starting to think I should just ditch the hornorum to mossambica cross breeding (for mono culture) and just go with 100% hornorum. I am liking everything about them. Then mossambica are shy, only eat when you are not looking and they spend a lot of time chasing each other around; agressive.

I don't find I have a problem raising mixed-gender fish for eating. The crowding eliminates a lot of the aggression, and since I'm not trying to harvest all at once, the differing growth rates is actually a good thing.

I'm having trouble getting two pairs of Tilapia to breed. Removing the top lip on the males has kept the females alive -- but battered.

Once tilapia are 4 or 5 months old are they safe from being eaten by the larger tilapia?

I guess what I am asking is at what point can they all be in the same tank?

I am going to be raising 12 batches of tilipia at a time and it would save money if I did not have to have happa nets for all 12 months

Well, there's outright-eaten-in-one-gulp, and there's battered-until-dead-and-then-eaten.

I do have a mixed-age group in my tank with about a 6-month age difference. I have had a few mortalities in the younger fish, and have not always found the bodies quickly enough to determine cause of death. The bodies I have retrieved did not look battered, but the bones I picked out of the filter told no tales.

Today's Headline in South FL.
Cooler weather fatal for exotic fish! We had a cold spell (70 for high and 59 for low) In the last 10 days workers have hauled off more than 10,000 pounds of dead tilapia from canals and lakes in Palm Beach County. Death due to spawning stress and cold. Dissolved O2 levels were fine. The vultures are having a feast! This just reinforces that spawning needs warmer temps.

( And keep the vultures away!)

Would a 12 month old tilapia eat a 6 month old tilapia?

Very interesting. Wonder what temperature that made the water and what temperature it normally runs at.