Overflow not flowing so well...

[Jan]

Hi,

I have a CPR overflow box plumbed between my 30 gallon cube and my shared sump. I have a durso standpipe in the back of the overflow, with a 1/8 " diameter hole in the top of the pipe's cap. There's also an airline tube sucking air out of the top of the overflow, via a small pump that's in my sump.

Last night I noticed that the water level in the overflow was high, and the water level in the cube itself was so high that it was about to overflow.

What things should I suspect, as the cause of the imbalance between the out-flow and the return-flow? I couldn't see anything obvious. I used a turkey baster to blow a little air in through the hole in the durso, in case it was getting clogged up in there...to no effect. It doesn't look like there's much of a bubble built up in the top of the overflow either. There is a little bit of macro algae growth on the inside portion of the air outlet (top of the box). It might possibly be restricting the flow of air and water into the airline tubing. However, because it's on the inside top of the overflow box, there's really no way to get at this algae to remove it.

Has anyone had this kind of problem before?

 

[prbhasson]

Check the pump that is hooked to the overflow box. Most of the time the tubing to it becomes clogged and the pump will stop sucking the air from the overflow causing problems. this is the reason I removed my CPR overflow. Tired of water on the floor. Very poor design. you should switch to a U-Tube type overflow. You will no longer need a seperate pump to keep it primed and it will not overflow in a power outage...

 

[Jan]

I'll check it out....thanks.