CPR CS150 Deluxe Aquarium Overflow Box

First, very quick shipping. Now, this HOB Overflow is awesome! i ordered one a few months ago even though they were said to be loud & loss of siphon without an aqualifter, although it hasent happened to me i can see the possibility. order the aqualifter & no worries. it does the job awesomely it drops water like no other single bulkhead HOB overflow. it is loud but easily fixed. i used a piece plastic grate(the stuff used to hold up the bioballs in the sump) cut to fit the back inside the overflow box. attach bioballs end to end creating a string fit to inside the back of the box, 2 layers highest point at the waterfall add filter media strip 3 inches x 9 1/4 inches on top of the bioballs up against the waterfall tucked to create a spillway as the water flows over the filter media & down. dont cover all the bioballs leave the back set uncovered this allows water to trickle over all the bioballs without clogging. after that its SILENT. i run this hob in my bedroom at 1500 gph (mag supreme 18 sump pump)4 feet from me & barely hear anything.<br>