Aeration water volume mixing chart presented by esshup has valuable information as it was produced by actual testing. Note the lifting rate is in gallons per minute; then X 60 for gallons per hour. As you can see from the chart diffusers move MORE water when placed deeper. It makes no ecological sense to me to put diffuser water lifter circulators in water in 10ft -12ft deep when the pond is 18ft deep unless there is a special situations, which are rare.
Then when diffusers are at 10ft-12 ft deep this results in water deeper than 12 ft developing no oxygen (DO) and the sediments become anoxic (aka anaerobic). In this condition,,, black sediments are created, hydrogen sulfide and methane gasses are created and pH is reduced and various forms of decomposition of organic sediments are decreased 20 to 30 times; not 2 to 3 times but 20-30 times slower / less. Now how does this make sense? If someone does not believe me then just test the DO in the water below the depth of the diffuser head. Circulation of the pond water only goes as deep as the head lifting surface of the diffuser. This is due to differences in water densities. I have tested this very often and it always holds true in normal situations. Not everyone in the "pond business" is well versed fully about diffuser bottom aeration - especially when you haven't actually tested it.. "YOU DON'T KNOW WHAT YOU DON'T KNOW" via Bob Lusk.
esshup is correct - During ice cover especially with a snow cover blanket shallow diffusers can be very beneficial when operated enough to daily create an open water area so light can penetrate and naturally plants and phytoplankton make DO in the shallow open water zone. Circulations from the shallow diffusers move and mix good water for very far distances when the water is densest and very easily mixed and distributed when at 39F.
Last edited by Bill Cody; 09/12/25 07:53 PM.
