Quieting my overflow to sump?

[Reefbox]

My water is making noises in the vertical pipe (drop) to the sump. I have a silencer on the top inlet, it's quiet.

I have a 2" and 1 1/2" overflows to sump.

If i add a gate valve at the bottom of the 2" pipe 4 control into sump will i be able to keep it quiet? Keeping the vertical pipe mostly filled with water. I'll keep the other overflow slightly higher as a backup.

Will this work or is ther a better method?

[Reefbox]

A gate valve holds a vertical liquid level in a protein skimmer more precise than a ball valve.

So a gate valve should be able to keep a precise amount of water in the vertical piping to my sump, eliminating te dropping water noise?

[Capt_Cully]

My 70 is in our bedroom and it sounded like the loudest part of a toilet flush...ALL THE TIME!

I added a ball valve to the tubing coming from the overflow. Quiet as a mouse!

You gotta be careful though, it takes time to dial in. Too much, you risk overflow, too little and the water will catch up intermittently creating a WOOSH.

[Reefbox]

I added a gate valve to the very bottom and I'll see if that will keep it quiet and function properly.

Fortunately on this tank i have an extra overflow run to the sump. So this should be quiet and safe.

[fishtk75]

Originally posted by Reefbox
I added a gate valve to the very bottom and I'll see if that will keep it quiet and function properly.

Fortunately on this tank i have an extra overflow run to the sump. So this should be quiet and safe.

First you never want to put a gate valve on the overflow pipe to the sump. You want nothing in the way that hold water back to the sump.
If something get stuck say algae in the valve the water back up and overflow the tank and on to the floor.
What type of overflow is it? Is it a syphon tube type
http://www.thatpetplace.com/pet/prod/237621/product.web

or is it a CPR type boxes?
http://www.thatpetplace.com/pet/prod/213290/product.web

I had a syphon tube type and the return side where the 1 1/2 pipe hooks up to the return pipe and made the same noise. I got 2" pvc pipe cut about 3" long. Now took the one end cut slots about 1 inch long and cut across to brake off so the slot is 1/4 inch wide and made 5 on the end of the pipe.
Now on the other end I got a 2" pvc cap put it on that end plus in the middle on top of the cap drilled a 1/8 hole for air. I took off the prefilter of the inlet then I put on top of the overflow inlet it cut 95% of the noise.
You may need to measure to see what size pipe to fit over the fitting in the over flow box.