I am fairly new to aeration myself (started my system in early summer this year and the pond had only been full for one year) and I will be starting my system back up next spring as soon as the air temps warm up above the water temps. I take water temp readings at 6" down, 18", and at the bottom (7 feet) from the end of my dock and will look at those readings for when the coldest water temp is below the coolest daytime temp. Once the daytime temps get above the water temps, it makes sense to start up aeration. I am trying to use the aeration system as a water warming mechanism as well as O2 provider. My theory is if I can warm the pond just a few days/weeks earlier and keep it warmer a few days/weeks later in the fall...I have added a week/month of a warmer environment which should result in a longer growing season. I may be splitting hairs with this theory, but using the air to water temp comparison makes good sense either way. There is no reason to cool the pond down early in the spring, just wait for the warmer weather. Now, switching to night time aeration instead of daytime during the heat of the summer can be important especially for small ponds.

I'm not convinced that my theory is really worth while because changing the aeration timing from night to days in the fall really messed with their feeding habits which could have nullified what warmth that I conserved. Next year is a new year and I will start the system up in the spring on days as soon as the air temps get above the water temps and switch to nights once my pond surface temps approach the low to mid 80's.

Whatever you do bring it up slowly...you know what I mean? If not, just say so and someone will advice on the proper start-up procedures. Bringing it up all at once can a bad deal.

Fish on!,
Noel