Hello! I have 2 down pipes from my HOB Overflow. I bought the ReefMat 500 Fleece Roller Filter - Red Sea and see that only 1 Overflow pipe is connected to the fleece roller. What do I do with my other Overflow pipe? Do I let it drain into the sump, turn off the ball valve or tee them together? I'm at a loss for what to do here. Thanks for any advice! Picture is of the Overflow I have.