For anybody even remotely interested in aeration by circulation, I've made an important discovery.
As you may know, I initially tried a Kasco circulator along with sweeper nozzles oriented in tandem parallel to the shore and the surface to try to create a "spin". Thinking this was a great way to keep the water quality high and the oxygen levels high, I proceeded with the project as stated. After a short period of time with the circulator I discovered that the "spin" was too great and I was getting high levels of suspended sediment.
I subsequently switched to a surface agitator of the same size (3/4 hp) and ran it only at night, but continued to run the sweeper nozzles for circulation. My water cleared up and the fish have been thriving. My Secchi readings were under ten inches with the Kasco circulator running and have since increased to 27 inches today.
Today I decided to run a full water column profile because we are partially into a tremendous hot spell. Here are my findings.
DEPTH TEMP DO
surface 78 8.5
1 meter 78 8.5
2 meter 78 8.0
3 meter 78 6.5
These readings were taken at 11 a.m. on July 15, 2006.
I retook the readings at 2:30 p.m. same day and the only parameter that changed is that the surface temp went up to 79 degrees F.
As you can see, I've completely killed my thermocline. I thought that by reducing the circulation I'd still have a band of cool water for the yellow perch near the bottom. I was wrong.
The good news is that I've experienced no mortality of any kind, the fish are feeding vigorously in the late evening (maybe too vigorously) and that I've got tons of O2 available.
If anybody wants to comment on whether my yellow perch are going to perish this week with highs near 102 degrees, feel free.
I did decrease the feeding schedule to only one second per day to try to keep waste products to a minimum. I've gotten this far with the yellow perch. I hope they don't die.
I also noted some crazy spawning activity in the little shallow corner. Big bluegill were rotating wildly around the nest, and chasing the 6.5 inch feed trained bluegill that I've recently stocked off of the territory. I may be mistaken, but it looked like one bluegill was pairing up with a female redear. No chasing, just gentle spinning. I hope I'm right.
