Sorry it took me awhile to get back to you on this. I actually have it taken down at the moment because I re-invented an air jet lift that will now fill the growbed. This will actually re-incorporate my original plumbing solution overflow. I think I may also go with a constant flood in the bed rather than the bell siphon.
That lift was doing roughly 150gph visual estimate with just 12 inches of water depth lifting to a height of 6 to 8 inches.. Mine with have a deptch of about 4 feets to lift 12 inches.. should be no problem at all.
