What do you do for aeration Bruce?
I'm getting away from membrane diffusers as they seem to flow unevenly over time and burp large bubbles. It's something that's easily seen in a tank setup but probably missed in ponds.
Common sense says it's due to clogging, but even after surface cleaning I still have issues. Of course the damn things are close to impossible to disassemble for cleaning the other side of the membrane without some kind of custom built tool. (I think someone told me Ted Lea had built one?) It would be nice to take them completely apart to thoroughly clean both sides of the rubber membrane with muriatic acid. They're too wide to sit in the bottom of a bucket without using a lot of muriatic acid to get the acid to cover them.
Funny thing is some of the membranes run flawlessy indefinitely while others have issues in short order.
I'm now gravitating to a dual pvc manifold with a nine inch stone on each side. No need to mount it to the center drain as it's self weighting. And it can be easily lifted from the tank for cleaning or flushing solids that collect around the center drain.
And it's a cheaper set up vs. the membrane diffusers and considering I'm now setting up my fourth high school with an recirculating system...
Believe it or not I am migrating towards pure oxygen systems. I have found some regulators that will go down to 1/64 of a liter per minute. You can run a small tank for weeks on that. Since it is only $11 to fill a tank I'm not sure that this is a more expensive than the power to run an aeration system. Plus, I'm not at the mercy of potential power outages. Using two different tanks gives me redundancy and healthy fish.
