I have to say that I'm very happy with this skimmer. After giving it time to break in and then cleaning it, it has been very consistant pulling out dark skimmate. No overflow problems which can be a concern with an external skimmer. It may be an illusion but the water seemed clearer within a few days of installing it. I know that the ASM G4x always pulled out a lot of skimmate, but it was more a light to medium greenish color. The Reeflo is pulling skimmate more of a iced tea to coffee color. I can also tell it is doing a better job because my tank glass doesn't get buildup on it as fast. The fish love it also because I have been feeding them more.