So I have an Eclipse L overflow with a "bean animal" style overflow (two horseshoe pipes and a straight emergency). The problem I'm getting is that periodically I get the flush. The flush get more frequent at high return pump flows. For instance at low speed it might "flush" once a day and at higher speeds its almost constant. The second siphon has a 1/8 hole on top to allow air in. My return pump is a Reef Octopus Varios 4. I'm starting to suspect that the pump has some variability in the settings and the swings are causing this. FYI when it runs properly its dead silent so Im fairly confident in the systems ability to perform as designed but something is periodically upsetting the applecart. Thoughts and help would be appreciated