More False Wall / Sump Design Feedback

[Doug]

OK, I see now.

It will be hard to have an elevated water level, and thus the skimmer higher and still have a low cap, unless the skimmer cup sticks out.

If using an ATO, the water level could be lower as you mentioned and then the skimmer, {again not sure on nano skimmers}, could be run in supm mode, sitting on the tanks bottom. Its also not water level specific in this mode and the cap could sit where you wish it then.