[Shawn]

Please help!!! I am having trouble with the u tube that connects the 2 boxes. Every other day i have to suck out air bubbles that acumulate in the top of the u tube. If i dont i will eventualy lose the suction. What can i do to fix the problem.

[Reefland]

How much water are you returning from the sump per hour? It could be that the full capacity of the overflow unit is not required based on your return volume. On the other hand, these types of units are known for loosing their syphon; a lot of people retrofit a powerhead inside the skimmer box blowing water through the U tubes to keep them flowing continuously. This also ensures that the syphon will restart if the power goes out.

Scott Z.

[eses]

I have the same overflow, mine will slowly build up air mainly because my return rate is slow. I've found if you increase your return flow from your sump it will force more of the air through and less will build up. Also with mine I have the piece of tubing that is in the u-tube running to the venturi inlet of my powerhead. It keeps a constant draw of water running through the tube and draws up any air bubbles pretty well. It also starts the siphon again once it has been lost.

[Reefland]

Running a piece of airtube from the powerhead is a clever idea! What kind of powerhead are you using for this? Doesn't this force air through the powerhead too though; shooting bubbles out of it?

Scott Z.

[Shawn]

That sounds like a good idea but my tank is acrylic and i think im going to drill it and use a bulk head.

[scubadude]

I had one of those overflows on my 90g when I had it setup...and if I remember right there is a small hose that you use to start the siphon with and if that hose isnt exactly wedged in the right place at the right depth then you end up losing your siphon. I do remember that O-flow being a pain in the butt! If you are real worried about it then I would get a more reliable overflow FWIW I have heard that CPR overflows are very dependable Hope you get it fixed!