I love the build, looks great so far. Dave has a very good idea with the baffles in the sump, one of the biggest cause for bubbles in my tank was the waterfall off my last baffle, this idea fixes that. One thing you could do to "failsafe" your ATO is to have your water enter the sump through a float valve AFTER your ATO setup. Since you won't be around for weekends, it could be very bad to have a switch stick on. Here's what i use for mine
http://www.jlaquatics.com/product/ro...O+Filters.html Up to you really, most people run just the ATO without problems.