TJ57 - Generally the more one aerates (bottom diffusers) a pond the more the bottom water approaches the ambient air temps. Thus aeration almost always warms the bottom zone while moving oxygenated water to the same area. The main exception is hypolimnetic aerators. Thus the air temperatures have a lot to do with how warm a pond gets even with aeration. A well mixed pond generally has a 1-2F temperature difference between top and bottom. Controlled or timed aeration can in some instances oxygenate the deep water while maintaing a cooler water zone. To do this effectively one needs a DO meter to monitor the conditions and have a "good handle" on all the things that cause DO loss.
Farmer Rick - Often larger lakes are deeper than ponds. This and the trophic status of the lake can provide a temporary cooler water refuge for the YP that is not available in ponds. If the lake has YP, they could survive in your pond. However much better chances of survival will be using a strain of YP produced in shallow ponds in your geographic region. Wild YP often have at least one type of internal or external parasite. Lake Erie YP often have red worms internally. Inland YP often have grubs of some sort. Tapeworms, trematodes, and flukes can also be problems in wild fish.
Last edited by Bill Cody; 11/13/09 10:35 AM.
