I have a hole drilled in my output tube just below the water level in the tank. If the power goes out it will not create a siphon and over flow my sump. Simple, but it works.
yeah. all you need is a siphon break. what is the wet dry hooked up to? A drilled tank? a tank with overflow box? and on the pump feed back upto the tanks. Just drill a small hole or two on the pipe just above the water line. and that will stop any back siphon
Looks like your gonna need some bigger barrels... Or more barrels... When I made my sump it didn't overflow ,but it got kinda high. So I attached an extra bin on it, put the pump in it, gave me a little more volume to fill...