Well my Reef Octopus NWM 250 is much more sensitive to water level changes than my Euro Reef. Of course it could be that the skimmer is 2 days old as well. But if it is this sensitive Im thinking it might be time for an ATO. The way my sump works is the last section is return pump and skimmer. It was one of those prebuilt acrylic ones from Pruess. If I knew then what I know now, I would have built my own. But that being said, the last section is where the water level fluctuates for top of. It maybe fluctuates 2 to 3 inches in an entire day. So what does everyone use for a budget friendly ATO. Im not having the desire to spend a couple hundred bucks on one. Just want a good simple one. Im assuming for all of them you have to buy like a maxijet 600 or something and a container? I have no experience with them, so any help would be appreciated.