Originally Posted by Reeffanman
Even the makers of that overflow box recommend using a tank with a built in overflow. That has to say something. And the pump is only used to prime the syphon not to maintain it.
Yes the point of the pump is to prime the overflow, but you leave it running 24/7. So if power goes out, tank drains. Power goes on tank fills, and pump reprimes the overflown. The only way this wouldn't work is if you pump isnt running.
I use the CPR CS90 Never had a problem with it. During water changes all I do is unplug my return pump. The overflow is designed to hold water in the U Shaped chamber so it wont back suck and fill with air and if for any reason it does, the aqualifter pump is there to suck all the air out of the overflow.