Hello, first off I totally disagree with you regarding the CPR overflow boxes. I have been running one on my tank for a year now with ABSOULTELY no problems. They have an air port on the top that you simply plug a 8 dollar air lift pump up to and it sucks all the air out of the box. I have turned my return and lift pump on and off literally 100 times. I have never so much as had a drop of water hit my floor from this overflow box not priming itself. It works great, easy to set up and clean. Just my .02 The CPR overflow boxes are great.
Fuzz