Dono - I am only aerating 3 hrs per day from 6-9AM in 0.7ac using 6 diffuser heads (3 separate diffusers) for strong mixing when it occurs. This schedule is a reduction from last year when I was aerating 5hrs per day at a similar time of day. Some other local YP pond owners with 1/3 ac ponds were running aeration 2-3 hrs per day with success and fewer adult YP deaths during mid summer. I decided to try the reduced time frame for experimentation to measure how much of my pond water column in a larger pond will be mixed on this schedule. Hopefully some temperature & DO data will be available in a few days. This 0.7ac pond is primarily a YP-WE pond and YP will tolerate low DO, but not the WE. I am still catching some WE in traps so I know they are surviving this aeration schedule and amount of water column mixing.
You assume correctly. The more or longer one mixes the pond the more the deepest bottom areas become warm and close to within 1F of surface temps. My goal in my summer climate is to have the coolest water on the bottom areas with adequate DO for YP and WE survival.
Question was "How would one guess on how much aeration is enough with out over heating the pond. I just run ours 24/7 and do find in the summer the pond warms up quite a bit."
Very good question with several variables or it all depends. Variables: pond size, pond depth, bowl shape, amount of habitat to resist mixing, size of compressor, number of diffusers, location of diffusers.
My goal has always been to have a minimum of 2-3ppm of oxygen on the deepest bottom areas prior to the aerator restarting. This maintains adequate DO for good aerobic bacterial and invertebrate decomposition of the sediments.
In your specific case in cooler summers of Ontario and if your compressor produces 3-4cfm 3-5 hrs of aeration per day should be ample to maintain good DO on the bottom for YP. In your situation running 24/7 is hyperventilating your pond and increasing the DO above 4ppm (mg/l) is not necessary. Warming the bottom water over 75F for YP may actually slow down the growth of the larger perch. YP growth will decrease in less than optimum temps, both high and low. As YP get above 11" and WE above 18", I think they prefer a cooler habitat for optimum growth rates. Smaller YP grow good in 80F-86F water, not the big ones.
Last edited by Bill Cody; 09/08/15 01:54 PM.
