Tilapia Breeding

Water flow through my 2 breeding tanks where I had the mosquito problem is a bit over 100 gallons per hour. Both have a couple of 8" air stones and the water is very healthy.  I think the real culprits were the eddy areas around the pots and pvc which allowed quite areas for the mosquito to lay their eggs in the gravel.

I wish my fish would have taken care of the problem!  I was vacuuming up 200 - 300 mosquito's per day from the porch ceiling.

No gravel - no problem!

Dave, I believe it depends on the type of prawns/shrimp. There's a type of fresh water shrimp that's being raised here with tilapia. Well, in the sump usually. Not directly with the fish. They grow very large.

The midge larvae, also called bloodworms, are GREAT food. For fish, I mean. If you have them growing in your system, you're blessed, in spite of the swarming. :)

Yea, I was gonna say, how were the mosquito adults laying eggs in the gravel in a tank?  They do it from the surface, and the mosquito larva are free swimming wigglers.  It would be the midge larva living down in the gravel.  And midge larva are good fish food and apparently in some tests feeding some midge larva to the fish increased the feed efficiency of the other food given as well.

cool

good to know

I will try them

@Jon @TC - pretty sure they were Midge larvae.  I definitely had the the little red worms by the thousands and the adults match pictures I've found.  That explains why the mosquito fish & rings didn't work and why I wasn't bitten by them.  I always thought the ones I was vacuuming up looked kind of large for a baby mosquito.  Thanks for the info!

The pools would be used for aquaponics. Why do you think they would not work?

some people have used kiddie pools successfully Christian, however, some pool liners contain chemicals meant to kill algae and bacterial growth and can become toxic to fish.  I'm not sure how to tell which pools contain the toxic chemicals and which do not.

Some people have used the pools and just killed batch after batch of fish.

Depending on the size of the pools, they may be difficult to net the fish out of.

Depending on the type of pool it might be difficult to plumb through it or support grow beds over it.

Not saying it wouldn't work but there will be some challenges and risks to trying it.

Yes, midge fly larvae are excellent supplemental fish food, and they do help a bit with detritus.  Virtually every system has some, even if you never see them.  If the eggs are laid in a tank with no substrate for the larvae to hide in, you'll be able to see them better.  They live their early lives inside of a "tube" and poke their heads out to eat whatever is in their vicinity.  If you see a bunch of brown tube like things on the bottom of a tank, that's likely the old homes of some midges.

 Midge fly larvae are sold in the aquarium trade as blood worms, and are fairly expensive.

MFL is a favorite food of trout.  As a result, fly fishermen often use flies (lures) that look like MFL.  I've got a bunch myself actually.  Work great in trout streams in the Missouri Ozarks areas.

Thanks for the input. Anyone have any other suggestions on what tanks we can use? We need minimum 5000 gallon tanks to make it worth while.

They do make big tank liners and there are above ground pools that are designed for growing out fish.  Aquatic Eco Systems has products that you might want to look into.

Different topic. I have found 3 dead tilapia in the last couple of days. They were all small one -- a couple of inches at most -- and my theory is that the bigger fish (4 inches or so) are denying them food or injuring them. Or something? The fish don't look sick or hurt or anything. No lesions or growths. Any theories? 

Thanks for the help TCLynx. Will look into them.

Thanks for your comment Jon but I'm not using heaters. I live in South Florida (the Keys) and our ambient air temperatures have been in the 70s and 80s. The water has been holding steady in the mid 70s. I just checked the pH and it's fine. Here's a photo of the last one. 

T C I am one of those people who used a kids pool.  Intex was the brand.  I had used one that had been used as a swimming pool.  Because it had been used for awhile it was no longer toxic,  I was doing aquaculture at the time,  I decided to set up another one but I only put a few fish in it.  It killed them quickly.  I had another friend that killed 2000 baby asian catfish at the same time.  Thwy are not safe unless they have been up and used for awhile.  I suppose aquatic Eco uses onse that don't have anything in them

I guess not all pools are created equal, last year I used two Intex pools from June till August to hold my young catfish and tilapia. Bought the pools from Kmart the 1000 gal for 6 weeks then a 3000 gal till the middle of August. I had no problem at all, perhaps it was because I used a lot of air to drive 4 big sponge filters. I also setup 3 of those 8' fifteen dollar ones from Walmart to raise my guppies and killie fish in and they were safe as well. However I used a large plastic garbage can as a filter for 500 gal pool made of 2" X 12" lumber lined with black plastic sheeting and that killed some fish so I replaced the garbage can with a black tote tub for the filter and all was well. I put a few guppies in a new pool to test it, if they live a day or so then its alright to use. Over the course of my 60 years raising fish as a hobbyist and commercial fish farmer I've used dozens and dozens of above ground pools without any bad happenings, of course there could be a first time just around the corner. 

Yep, kiddie pools sometimes work and sometimes at your own risk.  Now if it is just a small backyard thing and not many fish at risk, then it isn't that big a risk.  But if talking about going for a commercial scale operation, perhaps maybe getting something that some one can definitively say is fish safe is the option I would probably recommend and hence the recommendation of looking at Aquatic Eco systems for the Fish safe Pool.

MIchael, I assume you've checked all your measurements? Ammonia, nitrites, nitrates & PH?

Your dead fish might just be due to territorial issues. Were these floaters or did they jump out? If you have mature/maturing tilapia, the bigger ones will get territorial and chase the smaller ones, sometimes incessantly. Smaller fish will even jump out when they're running from the perpetrator unless there's a cover. They won't have injuries in most cases. How many fish do you have /gal of water? And what is the size range of your fish?

Thanks Sheri. Yes, the numbers are all OK. It was a floater as were the others. The fish range in size from that of this one, rather small, to others that are about 4 inches or so. I started with 50 fish and 6 have died. They are in a 300 gallon tank. The large fish all seem fine, eating with gusto. I have been concerned that the small fish aren't getting enough food with the big ones eating all of it. I have been feeding with a couple of different sizes of food because of that concern. 

Michael, are you able to feed as much as they will eat in 15 minutes without having water quality issues?  If so, perhaps you can spread it around and feed a lot at once to see if the little guys get a chance to get to the feed without the big guys getting it all.

And sometimes the runts are not all that robust and it isn't uncommon to loose a few, though 6 out of 50 seem more than enough losses unless you got a lot of genetic rejects.

What I've observed with ours is if you feed enough, the aggressive ones fill their bellies and the remaining food will eventually be eaten by the smaller fish, usually after it sinks. I think our smaller ones survive on algae as well.

Other factors might be aeration, PH (but you said that was OK); possible pollutants like insecticides, even natural ones, and leaching; and temperature. If all that pans out, do you think there might be something that changed in the source water?

So many factors. pH is OK and I'm using cistern water so pollutants "shouldn't" be an issue but who knows these days. We live in an area where there is no agriculture and they haven't started spraying for mosquitoes yet. Temperature is fine; the water is about 75 degrees. I did add some water to the tank yesterday so that "could" be the reason. The water was a little colder and the pH might have been a little different but not significantly. 

The water is brown and not clear. I wonder if I should change out 1/3? Problem is, if I do that then the changes of water will be exacerbated.

TCLynx: I had thought it was as much as they could eat in 5 minutes. Is 15 more reasonable? 

In a normal home aquarium 5 min is the rule of thumb, but tilapia aren't normal.:) I'm glad to hear TXLynx say that, because it supports how I've been feeding.

This is just a thought, but my concern is that they died so close in time to each other. If it were just food, it seems they'd be more random, and fish tend to pick on weak ones so it seems like there would be signs of bites & things.

You changed water yesterday but they died over a few days? Did any die before the change?

I didn't actually change the water. I added water. I get evaporation from the plants and from normal evaporation so I have to add some occasionally. Also I wanted to give the fish more room by keeping the water level higher. I have been keeping a log of everything so I will monitor all of these factors more carefully. Thanks for all your help. 

Amber, Tea or brown colored water is common in aquaponics, the fish don't care.

If ammonia and nitrite are 0 or only a trace (below .25) then I wouldn't be worrying about doing water changes unless you suspect some contaminant in the water that would be improved by changing the water.

Thanks for pointing that out. As a newbie I have concerns about EVERYTHING. So this put this issue out of my "worry box." 

tinted water is fine.  The earlier comments/questions about DO are of interest though.  Make sure you have plenty of aeration.  I've noticed fish not eating as much as I would expect when the dissolved oxygen levels got low though not dangerously so.  And if there are any spots where uneaten food or fish poop are building up in the fish tank, that can also be a cause for concern since a build up of such things in the fish tank can become anaerobic and when stirred give off toxic stuff for the fish.  It is also possible that such build up can deplete a tank of dissolved oxygen if the aeration isn't sufficient to keep up.

Jon, do you use the Ultra frames or the regular blue frames? Thanks

I added more aeration today so we'll see what happens. The tails on the dead fish have been bitten so I'm guessing that it's the big boys chasing the little ones. 

christian if you google pool liner above ground  there are a couple that say they offer the liners that are aqua or fish safe they will even make them to fit whatever pool or frame you have  take a look also aquatic eco offers a liner that will fit a roll off dumpster like the ones used at construction sites.

Michael, after looking at your picture again, you're right-the tail has major damage. Given the size, your fish are maturing and probably starting territorial/mating behaviors. The little ones take the brunt of it.

Thanks Sheri. Is there anyway to protect the little ones? I found another dead one today and it looked pretty beat up. Or do I just let nature take its course and fill in with fry as they come along? 

John T and Jon P thank you guys for the info.

Michael, one way is to overcrowd them, oddly enough. I may have missed this in your posts, but how many fish do you have, how many gallons of water? 

Just speaking from experience, we've had our fish/water ratio at about 1/5 gallons, and have never had problems. As they've matured and grown, they've become more crowded.

I started with 50 or so the seller told me though, frankly, it never seemed like there were that many. About 10 have died so, theoretically, I'm down to 40 but they are in a 300 gallon tank so the ratio is about right. The initial problem was that when I received the fish a few of them were noticeably larger than the rest and they might be the troublemakers. I had no problems at all during the first month but now I'm approaching month 2 and that's when I've had the die off. I checked everything again this a.m. Ammonia zero. Nitrite zero. pH 7. Mysterious eh? I put in some pieces of PVC pipe so they can hide. Maybe I need one of those fake rocks with holes and stuff so the small ones can get in there. 

I have 100 in a tote and 3 grow beds that are 1/2 of a 55 gal drum but they are all the same size I try to seperate as close to size as I can. I have my breeders in a separate tank .

I see  you added water Michael did you let the water run directly in to the tank water hard or slow I did it once letting my water hit the sides of the tank and directly in the water hard and ended up with so dead fish and could not find any reason for it so I think this was my problem

I thought of that too Lonnie. It's possible. The water didn't come into the tank hard (no sprayer) and, in fact, the fish seemed to like it, hanging around where the water was coming in. 

yea mine liked it but I did have mine to hard what is the size range on the fish I have some tanks that have from 1/2 in to 2 in they do chase but not constantly but I do have 100 or more in tanks so the bullys have more to chose from

I got them as fry and some now are as big as 4 inches while others are only about 2 inches or even a little less. Only the small ones have died. I started with 50 and probably am down to fewer than 40. 

yea that is alot of size gap that may be all that happened

They're small, but getting to the mating and territorial size/age.300 gal for 40 of your size is a lot of space. You can still crowd them more. Even as they get bigger you can handle up to 50 or 60 in your tank.

Here's one thought: you can reduce the amount of water in the tank by about 100 gal. Observe for a while, and if they settle down you know it's the fish/water ratio.

The other thing would be to separate them. The problem with this is you'll end up with fish of varying sizes anyway. The more aggressive ones grow faster than the others.

Perhaps some milk crates or another object in the tank that would allow the smaller fish to swim through but make the bigger ones go around so that the little ones would have an easier time getting away?

What is the smallest size Tilapia you guys have ever had breed?  My largest are about 3.5 inches.  I wondering if they might start breeding soon.

anyone know where I can get some breeder colonies at a decent price? looking for all male or almost all male offspring. Thanks

What does a pink nose on a tilapia mean? 

Taylor, I think ours were around 6" when they started to breed.

Christian, from what I've seen most breeders aren't very affordable. :)  But having put together our own breeders, it can take quite bit of work to make certain you have a good colony.

Breeders will produce mixed offspring unless you do something about it. Some give the new fry a testosterone wash which turns them all male. I also read a paper that talked about raising temperatures on the new fry to a certain level to produce majority male.

Michael, on our fish it means they've been bumping or rubbing their nose against something.