I've been skimmerless for the majority of the last 3 months. I've been having problems with my skimmer and then I decided to dose for the cyano. So far I think my zoos are actually looking better. I also don't miss the noise from the skimmer. I think I'm going to put it on a timer to come on at night for a few hours. When I did have it on it didn't pull much gunk anyway.