i have 2 600gph pumps to run on the tank. i wanted 2 smaller ones just in case something went wrong with one i could still run the filter.Looking good. The idea of an overflow is to keep surface clean and moving, but it's also good to keep water level at a constant, you will have a really tough time getting output from the fx5 to match your pump output, and as the fx5 get dirty and flow is reduced you will need to adjust your pump. I'd say it would be pretty much impossible
i'm not very good with overflows. whats a good one for the 2 pumps i have? or should i go with 2 overflow boxes 1 for each pump?