I think at 7 CFM it is ok for shallow ponds. I would just be interested to know how much volume it loses at different depths. For example we have a linear compressor with a max volume of 5.1 CFM, however at 6' it is already down to 3.5 CFM and at 8' it is producing only 1.6 CFM. Can you see the jump in volume loss from 6' to 8'? Has the manufacturer put on any literature on how much volume it produces at different depths?
I am glad to know you never had a fish kill or any significant problems with your pond. However, I would be very cautious of advising someone to implement a system like this with out having more information on the volume it puts out at 12'. Especially after someone spends a lot of money on stocking the pond. I know we all want to cut corners and do thing as cost effective as possible, but sometimes in the long run it can end up costing us more.
