I'm considering upgrading to one of these tomorrow. And for some reason, I can't wrap my brain around this right now. What happens when the water level evaporates by 1 inch and the left chamber does not spill over to the second (middle) chamber? What stops this from happening so the return pump doesn't suck air?
The reason I ask is because in my current system, I have a wet/dry sump with 1 chamber (with bio-balls removed long ago). When the water level used to get low (say, when I'm on vacation), the sump level would get low, but I would add water when I got back. No problems.
With this new system, it appears if my water level drops by 1 inch (or just below my built-in returns from the display tank), it'll cause an issue where the water won't fill the sump, and my return pump will suck air.
I appreciate your help!