First off I know that most of you have pre drilled tanks and this probably doesn't apply to alot of people out there but anyway. There has been alot of bad reviews on this CPR overflow in different forums. The problems is: the tube used from overflow top to the
power head once inserted goes down too far into the exuast water flow from power head. Thus, not pulling the excess air from the chamber of the overflow which in turn the overflow does not keep the syphon going and soon you will have a room full of salt water and the nice beach aroma in your house! To fix this problem cut a small pie shape out of the end of tube that will be inserted into the power head and this will allow the air to be pulled out of overflow chamber!! Ta Da You should have a little gasp of bubbles every couple of seconds which is a sign that the powerhead is doing its job for the overflow to work!! Give it a try I hope this helps somebody that has had the misfortune of having a overflow in the house FE Gunny Sends
