couple of things:

1. i would put the skimmer feed pump in the same chamber as the return pump and the skimmer drain before the tripple baffle, no in the middle of it.

2. unless you have an auto-topoff system, you will have a hard time keeping up with adding water to replace evaporation. the evaporation of the entire system will show up in the return pump chamber, which can cause that water level to drop drastically since you have such a small chamber there. i would suggest an RO water reservoir somewhere that drains into the return chamber via float valve or auto topoff controller, that way you just have to fill the RO tank every so often.