Simplest solution to me would be go with a bigger sump, and lower baffles so there's plenty of unused volume. I actually have two sumps tied together servicing three (soon to be 4) tanks. Even though the sumps can handle the water from back syphon, I still utilize George Fischer wye check valves on my returns. I also have anti-syphon holes drilled on the back of my returns. I hate water on floors, and somehow manage to get them wet for other dumb reasons, like turning the wrong valve when doing a water change and walking away for a minute lol
