FYI you could plumb that tank in a way to prevent it from draining without the need to rely on check valves or batteries. You could also run some of the pumps inline with the overflow to form a "sort of" closed loop, it would prevent the massive amount of sump turnover

I can't help it, I just can't take it anymore, I need to know your plumbing plans. 4 return pumps and glass that looks like swiss cheese, if that doesn't get you existed nothing will
