I have a g2 skimmer with a meshwheel sedra 5000 that runs all the time, yet pulls out very little scum. Probably because I feed very little. I have a fuge with a piece of cheato that is 1' x 1' x 6" deep and 5 small mangroves. I do about 30 gallons water changes once a month with r/o water. My water is 20 ppm last I checked. I plan on getting some DI resin soon. No dsb.