On the Rena Filstar XP3, I use one on my 75, I use it to run purigen by seachem in micron filter bags. I split one liter into 2 bags so I can regenerate one every month. I open my filter up every week to two weeks and rinse the foams in the washer with my filter socks. Upsides, quiet, effecient use of space, effective filtration. Down sides, it has a tendency to hold about of inch of air at the top of the filter and occsiaonly blow micro bubbles into the tank. It does for a couple of hours every few days. I do not like the two prong cord. More things I like, the double gasket, the intake and return hose are high quality silicon, it comes with clamps, I like the quick disconnect, and I like that I can see into the filter box. HTH I am ignorant on the subject of ozone in the reef, MAYBE Mojo would start a thread with his experince on it and help us who dont know much out..... LOL Steve