AZ - Since you are in the north (southern Ontario) and water temps are still fairly cool, I have had good success putting the diffusers on a stand or frame that gets them off the bottom and yet still in the deep basin into around 17-18 ft of water. This will reduce the operating pressure of your compressor to around 8.5-9 psi and this will lengthen the life of the vanes and bearings. When you start aerating in spring with diffusers on a stand while pond is still unstratified the entire water column of smaller ponds will become completely mixed.
