I have a cpr aqua fuge http://www.cpraquatic.com/products/aquafugepro.html and want to put my pump for the skimmer in the first compartment where the water enters it from the display. When i try to do this it drains all the water out of this and stops the flow through the fuge. When this happens should i fill the first compartment up with more water so it is at its normal operating height? Or do i need a new sump that is set up differently.