This has been a very enlightening discussion. Other than carbon and Phosban I have only used a sock at the skimmer output to reduce microbubbles. It was of mixed success.
Below is a photo of the back of my tank when it was first being tested for leaks. You can see that there are 2 overflows. From left to right chamber 1 = now full of LR rubble, Chamber 2 = skimmer which empties into Chamber 3, Chamber 3 = refugium, Chamber 3 = return pump and heater.
Any ideas on how to use socks at the overflows? Currently using floss with marginal success.
