Originally Posted by Tboy
does it always have to 5-6 inch. in water other wise it doesn't work right?
Whatever the manufacturer's recommended depth for submersion. In essence, as long as the pump is under water you should be okay.
Of note, at least for my AGA/MegaFlow sump system, changes in water level (evaporation) are reflected in the sump, not in the tank. In other words, the water level remains constant in the tank, but changes in the sump, so if your system is similar then careful observation is recquired to maintain proper depth.