so on my 125big i run a HOB overflow box for my sump. the sump is a Eshopps WD-200CS Wet Dry Filter - 150 to 200 gallons - 30 in. x 12 in. x 16 in. with an older mag model 7? or something like that.. my question is in the HOB box there are TWO of the U shaped syphon tubes that move water from the fron box to the back, at any given time i have a steady flow in one but the other not so much.. it always seems to be just one tube and not both.. thinkin things thru, i first decided to ask here for advice prior to my not so smart ideas..how do i or can i get both to be a steady flow? do i need both? is it btr for both to flow? (im a big fan of over filtering btw). also on top of my sump, i run two Penguin 350's and a powerhead for added filtration and circulation.