Pond Boss Forums AERATION Should I aerate? Cold spots in pond used for swimming, help please!

Bottom aeration will eliminate the cold spots. Warm cold spots form in calm wind warm or hot weather due to uneven heating of the water. Often the warm spots form where zooplankton congregates and as a group the absorb more sun rays - warmth. Bottom aeration diffusers will turn over the whole pond (1/4 ac) and regularly mix the water minimizing the warm cold spots. In Ohio a good bottom aerator (1/4hp) need only run 4-8hrs per day in a 1/4 ac pond to get complete mixing. I would run aerator 3-4hrs before swimming. Smaller sized fountains (1/2hp) tend to not mix enough water rapidly enough to eliminate all cold spots. Fountains tend to mix water primarily just in the vacinity of the spray zone with some downwind current drift due to wind action. Fountains are more costly up front, more costly to operate, and require more cost and maintainance time due to water pumps not lasting as long (bearing life) as compressors for bottom aeration. Fountain motors work harder than air compressor motors. thus more repairs.