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navy guy
01/17/2007, 09:26 PM
I have recently placed a Quietflo hob overflow rated at 600 gph on my 72 gallon bowfront and it is making random gurgling noises. The piping is 1" leading into the 10 gallon rubbermaid sump in the stand. Between the overflow and the sump I have a ball valve that is throttled 1/2 way closed to try and lessen the noise. Exiting from the sump I have another ball valve and a union fitting before my little giant external pump that is rated at 640 gph @ 3 ft head. On the other side of the pump is another union fitting and another ball valve. This valve on the outlet of the pump is throttled half closed as well because the pump is filling the tank MUCH faster than the overflow is pulling water from the tank. There is a 45 degree fitting coming out from under the stand and then 2 90 degree fittings leading up over the back of the tank. The overflow is giving me the problem. I am experiencing about an inch of evaporation in the sump each day. The water level in the tank is not changing and there are no bubbles in the "u" tube going from the tank into the overflow box. Any ideas would be greatly appreciated. Would drilling the tank be better or would I still have noises?

BryanJ
01/17/2007, 09:36 PM
make a baby durso pipe to fit in the overflow box

fkshiu
01/17/2007, 10:00 PM
Sounds like your pump is overwhelming the overflow which can't keep up.

A Stockman standpipe would be a better option for an HOB overflow.

http://www.dursostandpipes.com/

(see the "Popular Modifications" tab)

You should also try to have the water exit right at the same height as the water's surface level of your sump in a horizontal fashion (with an elbow at the end) so the air can escape into the atmosphere rather than underwater creating air bubbles or splashing if its above the water's surface.

Remove the ball valve from your overflow side as you run the risk of flooding your tank. The overflow is designed to run unimpeded. You should control the amount of water going in by throttling back your return pump with a valve AFTER the output of the pump. By adjusting the pump output and the height of the overflow intake box, you should be able to balance the amount of water entering/exiting through your system and reduce noise.

The Quietflo is only designed to handle about a MAXIMUM of 600 gph. Your other option is to get a less powerful pump. That Little Giant is probably pushing too much water too fast through your little sump.