A diffuser will have a CFM rating range. It will operate most efficiently within that range. Too little air and it will not perform as well and too much might over stretch and damage it.
So the first order of business is see what CFM the pump puts out at the depth you will be operating.
If we assume the pump has the capacity to deliver air that is within the range of either a single OR double diffuser, then the double will likely do a slightly more efficient job of moving water. Probably not a huge amount better, but some better. At least one reason being the bubbles seperated slightly in columns tend to grab more water between them as they go up.
That is what you are doing with aereation. Moving water from the bottom of the pond to the top where is can take on O2 at the air/surface interface. So moving water is the key and the bubbles are what moves the water up.
So if you have a pump that is getting toward the upper limit of what a single diffuser will handle, might want to go double. If you are scraping the bottom of the barrel for CFM barely making it into the range of a double, might be better to stick with a single.
The whole thing is, figure out how much air and turnover you think you need, then size the pump and diffusers to that need. It is as much of an art as it is a science.
No expert here. Just what I have learned from the big boys.
John
Last edited by snrub; 01/08/20 07:23 AM.
