Getting a little concerned here in the U.S.!

[Cecil]

This summer has turned into a real scorcher and my coolwater fish which are Yellow Perch (Perca flavescens) may be a little stressed in the outdoor ponds. Not much feeding as they are probably sulking on the bottom. No morts that I can see though. Fortunately even though they are originally Great Lakes fish, they have been pond cultured for about 30 generations and my original supplier thinks they have adapted to warmer water.

I'm considering running the well into the pond which I have never considered for this species! Only problem is it has to run through another pond first and there is a risk of bluegill (Lepomis macrochirus) fry getting into the pond which I don't want. If I do run the well I'll have to seal the overflow well pipe with something fine mesh such as the wife's pantyhose!

I do run a compressor with two diffusers that mixes the water column to keep D.O. up in the deepwater but I've been running it only at night to keep warming down. It's catch22. I could have not run it and had much cooler water in the depths but the D.O. would have been low there.

Anyone else having problems with extremely hot weather in the U.S. or elsewhere? I hear Europe has been hit hard too.

[Crusty]

How deep are these ponds Cecil? And what is the water temp at the surface, 1meter and the bottom. If they are shallower than a meter (3foot) there will not be much you can do.

[Cecil]

How deep are these ponds Cecil? And what is the water temp at the surface, 1meter and the bottom. If they are shallower than a meter (3foot) there will not be much you can do.

The .62 acre pond with the biggest perch is about 11 feet max with losts of 8 foot plus water. The other pond with the male broodstock, which are smaller is about 9 feet max but only .10 acres and drops off quickly. It use to be my trout pond when I ran in the well.

I cranked up the well today that enters the .10 acre pond and stretched pantyhose over the overflow pipe which overflows into the .62 acre pond. Then put a large screen over that. I've got bluegill fry in the .10 acre pond I don't want in the .62 acre pond. I will periodically check the hose for clogging and replace clean and rotate it. I do know from experience once the water has exchanged in the .10 acre pond it will not go above the mid 60's on the surface, which means mid 60's water will be flowing into the big pond. I think from experience I can keep the big pond under 80 F. and since 77 is optimum temp for the yellow perch that should be good.

Water right out of the well is only 52 F. Although that is a drastic temp change there are no worries about too quick of a temp change in this tepid heat. Low 90's today with lots of wind. It will take at least a full day or two to notice a significant temperature change in the smaller pond.

[Crusty]

Hi Cecil.

Have you any air lifts in the water column? A quick way of lifting the water up from the bottom of the pond.

[Cecil]

Hi Cecil.

Have you any air lifts in the water column? A quick way of lifting the water up from the bottom of the pond.

My compressors that run air to the diffusers on the bottom of the ponds are basically airlifts. They move a lot of water to the surface and prevent stratification of the ponds. However with cool and coldwater fish one has to be careful not to overdo it in summer. That is I only run them at night when air temps are down or they will actually warm the water too much.

[Crusty]

Are they running pretty deep Cecil?

[Cecil]

Yes in summer I have two of them spaced at an equadistance apart in the center and deepest water of the pond. In winter to prevent winterkill I have one set on the shallow end of the pond with much less flow to keep a small area of ice open for light penetration (photosynthesis) and an air water interface connection. The opening also allows a place for noxious gases to escape if need be.