I am located in NE OH and considering stocking some Talapia in my pond this season. We have had a warmer than normal Spring so far and the pond is active, alive and well. I am already seeing some FA bloom and was wondering how soon I can safely stock Talapia without risk of them dying off due to the water temp not being warm enough. I don't know my water temp... I have not measured the water temp yet, but I certainly can take a few measurements to see where it is prior to stocking. The fish farm says they raise them in 75F water so how much of a difference in temp can they tolerate?

You have to know the water temp first as that is the key temp - not air temp. I think it is not warm enough there as it is still too cold here in the south (but getting close here). I would not stock until the water is above high 60s.

My supplier invariably delivers my Tilapia on May 21 +/- 1 day. Is it warm enough some years that they could survive being stocked earlier than that? Yes. Can you guarantee that it will be warm enough every year for Tilapia to live if they were delivered earlier? Probably not in Central Ohio.

Slightly off topic:

Presumably the water in the truck stocking the tilapia is warmer than the pond water.

What is the procedure to release fish (any type) where the water in the tanks is at a different temperature than the water in the pond?

I have not seen a chart in the archives of the acceptable temperature difference for different species of fish. Does such a chart exist, or is there a rule of thumb that covers all of the most common species?

Thanks,
FishinRod

The fish stocking truck should mix your water in the hauling tank before stocking. General rule is 10 minutes per 1 degree water temp difference.

FYI there are at least 2 different temp issues. One is lower lethal temp for the species and the second is the rate of change. One is fatal and the second is also often fatal. Example - assume tilapia lower lethal temp is 55 - if water is 54 the fish will die but if the water is 60 and you stock from 70 stock water the rate of change will likely also kill them.

In addition if water is cool but above lower lethal and fish survive stocking but water stays cool (lets just say 60) for 2-3 weeks there will be little growth or feeding due to suppressed body function in cool water (metabolism of cold blooded fish is suppressed).

Thanks guys for the clarification.

I was asking about the temperature shock change to the fish. I knew there had to be a simple solution. I didn't know the haul trucks could suction from your BOW to slowly bring the fish tanks to the same temperature as the pond.

They either do that water exchange at the pond to the tanks on the truck (I don't like to do that because the added risk of bring back nasties to the farm which means more labor sterilizing everything) OR have a good idea of the water temp in the ponds in the area where they will be delivering the fish that day and do the tempering before the truck leaves to deliver the fish.

Depending on the fish, 3°F difference in water temp is safe. You might be able to get away with a 5°F difference with larger fish. Some fish are more sensitive than others. For instance Golden Shiners are more sensitive than Fathead Minnows.

For us here in Northern Indiana, water temp has to be in the mid 60's AND after Mothers Day weekend for us to stock Tilapia.

If the customer wants them stocked earlier, we try to discourage them, but if they *have to* have them we tell them if the water cools and they die, we will NOT replace them on our dime - they will have to re-purchase the fish. Lets just say that you learn some things from experience.......

It's not only temp, fish don't like large pH swings either.....

I've done tilapia in NE Ohio and they usually come in around memorial day or so... Where are you getting them from?

Plan to get them from Fin Fish Farm

Rod, this is part of the reason I used several buckets and a dipnet for each bucket when we seined fish at snrub's..
If you remember we used the tub with salt solution with pond water and a very small amount of well water to drop a few degrees. The freshwater bucket had well water that set in the black bucket that was yet ever so slightly cooler than salt solution. From there we went into the tank with pure well water. Using different nets and buckets was for 2 reasons, 1, to temper fish, 2, to not introduce ANS.