The last few days I've been turning an idea around in my head and wonder if anyone has any comments on it.
I've been thinking about putting in a very
small sump (on the order of two gallons or so) for the specific purposes of surface skimming and buffering evaporation. As currently set up, my tank looses about a gallon or so a week to evaporation, so the size is about right to buffer the evaporation. I do currently have some mild issues with surface film build up, and as this wouldn't be moving very much water it would mainly be filtering that surface film. Main filtration would still be a job for a real filter, of course.
I had in mind to build a small overflow box and move the water back to the main tank with an Aqua Lifter
type pump. The advantage I see with the aqua lifter, is that it wouldn't eat itself if the sump somehow ran dry. The challenge I see is that thirty inches might not be quite enough height for my needs, since my tank is twenty-four inches tall.
The thing I'm concerned about with the small overflow idea is the potential for clogging. It would require balancing overflow size with clogging prevention.
Obviously, there are plenty of details to work out on the idea, but I wanted to see if someone else might see some show-stopper issue I'm not seeing that would make the whole notion pointless.
I won't be able to actually do
anything on this idea any time soon, so it's very much a pure intellectual exercise for the near future. If it were to turn out to be viable, I see it as a possible way to add a couple of sump related benefits (skimming and evaporation buffering) to a canister filtered system, without adding some of the potential downsides that come with sumps (space, CO2
loss concerns, noise, etc.).