The only ones I've seen dead are big. Bigger than any large mouth bass could swallow.

Do they eat all the vegetation in the pond?

I don't know, but that was the idea behind putting them in the lake.

The particular lake I live on way back when used to be sprayed with cuperous ammonium Acetate and I think it was copper sulfate to control coontail moss and other native vegetation that would end up choking parts of the lake with unnavigable matts of greens. Then Grass Carp were introduced to do the job of the chemical. Then tilapia were stocked.

There is no visible submerged vegetation so something is eating it up. The only tilapia I normally see are smaller ones, very small, tight to the bank and a lot of the time with their mouths at the surface sipping something. If we dump a handful of range cubes off the dock, some bigger ones will come and gobble up that. Mostly I see the big grass carp. They like Spanish moss to eat because any that falls in gets worked over by them. The grass carp also like water oak acorns. They do not like whatever fly I present to them. The tilapia really doesn't either, but I never see one to cast to.

I think some extended cold weather will be good to thin out the herd of tilapia. If they get wiped out, we can always stock more. But I can't look anywhere up shallow against the bank and not see tiny tilapia.

A few years back I caught some tilapia out of a local DFW lake (very well known) in the middle of winter. I called the game warden about it and he asked that I freeze it. He couldn't get by the house, so he asked that I send a picture. He said "yep, that's a tilapia" and that was the end of it. He never did anything with the information to my knowledge.

They are algae eaters...don't actually eat plants, but they will sometimes kill plants while sucking the algae off them. Working together with grass carp (which do eat certain plants), the vegetation in a pond can be controlled nicely.

Nice fish.

It will be interesting this winter to see what happens with the tilapia in relation to the water temperatures. I think I want to get a thermometer that can take temperature readings at different depths. Anyone have a good thermometer to recommend?

I think I will get some this spring for my bass/bluegill pond and my catfish/bluegill pond!

See a lot of really big fish but anything I've seen or got over 4lbs have come out of power plant lakes where they live year round.

Several years ago, I overwintered several in a heated indoor environment,just for fun. Those grew to easily over 5 pounds the next summer.

...but the fastest growing fish I've ever encountered is the red belly pacu. Pet Smart sells them as cute little 2-3 inch fish...soon those cute guys outgrow everything and become monsters. I raised one to 17 pounds one year in a pond by overwintering it two winters. It got too large to handle. Amazing, stunning growth.