Gurgling PVC overflow

[redchaser]

Ok,

I finally got my return pump in, put together a return, hooked everything up and started running the tank.

a few observations

1. Flow rate with the 1.25 inch pvc overflow is great

2. It gurgles a lot

My overflow is built from the designs that have been posted around here. I do have a check valve installed up to. Is the gurgling caused by the height of the intake in relation to the water level (mine's a bit low)

Any suggestions for quieting it down?

Thanks,

Ron

 

[rallysman]

step 1:
put a cap on the vent tube with a 1/8" hole in it. If that doesn't work

step 2:
put a ball valve after the overflow and reduce it so the water can back up in the tubing and not splash as much.

 

[redchaser]

Rally,

I already had ball valves in outflow and return. I dialed back the overflow and it quieted down, of course I'd rather not slow my turnover rate. The gurling was coming from the intake and not the vent. I was wondering, since a bit of the gurgling seems to be caused by water falling faster than the intake pipe can fill up, would it reduce the gurgline if I made the overflow shorter. Less length of pipe, less volume to fill, less drop for the water to make.....?

 

[rallysman]

As long as your overflow is keeping up with your return pump you wont reduce any flow. Shortening the tubes will serve the same purpose as the ball valve, but you'll have less flexibility in flow rates. I've had overflows that were loud as hell, and the only way I could shut them up is to use a valve to keep a bit of water backed up in the pipes. Again, it won't kill your flow rate, but you'll have to keep an eye on it to make sure that food/dead stuff wont reduce the flow the point of overflowing the tank.

 

[redchaser]

Thanks rally. Actually I'm having to back off of my return pump just a little as it is, I'm running a quiet one 6000. Right now I've got a ball valve in line with the return, but I'm going to tee one off so I can reduce the return rate without back pressuring the pump.

 

[rallysman]

Don't worry about putting pressure against the return pump.
Since it's centrifugal it wont hurt it to valve it down, it'll actually help it. It seems like you would be making the pump work harder, but by choking it down it's actually doing less work, using less power, and extending the life of the pump.
A bypass is good if you're using it for UV or secondary filtration, but it's totally not necessary if you just want to reduce the flow.