Severe plumping problem

[djscribz]

I got my 20-20 plump together using a mixture of hard plumbing and soft (vinyl tubing) plumbing. The return output works like a charm, but the overflow is having some problems.

Im using a Mag 5 and a 1-1/2" bulkhead for the overflow. It is plumbed so that it enters a hose barb, short vinyl tube, PVC elbow, 1' PVC pipe, back to 1-1/2" vinyl tubing to the output.

The problem is the overflow is not a consistent flow, but instead a constant sucking. On very rare occasions, about 3-4 times a day air will get backed up in the plumbing and all push itself out in one big burst.

HELP!

The bulkhead Im using is a EPOM polypropalene bulkhead for the overflow and no standard plumbing parts will fit. I thought about using another 1-1/2" overflow, but the hole i cut in the tank is too big.

added pictures to show how it is setup


Problem Plumbing:


Problem Overflow:


Fine Plumbing:

 

[matttaylor]

On the 90 degree elbow coming out of the overflow, you might be able to drill a small hole, and the place some rigid airline tubing straight up (about 6" worth). This would allow air to escape, and still allow the overflow to function properly. Besides, if it doesn't work you can re-seal the hole with a little silicone. The air sound you hear is because the trapped air is creating a siphon effect and when enough air / water pressure builds the air is forced out. The rigid airline tubing will all air to escape out of the top,before it gets in the water path and as long as the top of the rigid line is above the waterline no water should come out.

 

[MrMikeB]

Maybe Ed could also chime in here. I know his system makes similar use of a bulkhead fitting and gravity (I think).

 

[djscribz]

yeah i ended up making a very ugly PVC vent using a t pipe. Its ugly but get the job done.

 

[matttaylor]

perfect. all the drain needed was a vent.