True about the overflow sucking the scum away. I forgot that my system is set up reversed from the typical setup. My sump is overhead instead of below the tank. So my sump overflows into my main tank. Anyhow, here is the surface of my tank about 10 days after I removed the Aquaclear. Its yucky. But I've repaired the Aquaclear and put it back online tonight. it should clear up the scum in a few days.
