Tank overflow to sump noise (Help)

[polifrone]

Just started my new 45 gallon tall tank. I've installed an internal overflow box with a bulkhead drilled throught the back glass of the tank. Water overflows directly to a 90 degree elbow and then down to my sump with two 90 degree turns (about 3-4 feet). I've installed a ball valve so that I can control the flow. Everthing works great except the excessive noise. I see a lot of information on durso down pipes but that seems to only work on bottom exiting bulk heads. I have installed a threaded strainer on the bulkhead which reduced the noise and I was able to reduce more noise by slowing the volume of water. If I reduce the flow anymore my pump will cavitate. Is there any tricks to get a full syphon by adding plumbing inside the overflow box (elbows,etc)??? Also, is it better to keep the overflow pipe entering the sump above the water through the filter sock or have the pipe exit under the water line in the first section of the sump? Any help or suggestions would be much appreciated.

 

[Planedoc]

A Durso can work in an overflow box if there is enough room for it. One thing you should never do is restrict the flow on your drain pipe. You really should not even put a valve in it. To slow the flow put a valve on the exit of the pump. Pictures can really help fix your problem

Sent from my galaxy s3

 

[yort265]

If you're trying to go for the "Bean Animal" or "Herbie" overflow and drain designs, you do have an emergengency, completely open, drain line correct? In that case you can restrict your main drain using a valve to attain a complete siphon in your main drain line, which is completely silent. If this is what you're doing, and your pump starts to cavititate before getting to the complete siphon, you may need a smaller return pump.

Did you mention there was an elbow on the inside of the overflow box? How's that elbow on your main drain line oriented? In the above circumstance, it's best to be oriented downward. If it already is, maybe you could try extending that elbow even further down into the overflow box using a small piece of pipe?

 

[GrampaDon]

1] Repeating the don't use a ball valve on the drain is a bad idea.

2]Thru the back can use a sorta durso. You can install a T inside your box with one leg of the T pointing up. Then add a short piece of pipe with a cap on it to the T [remember to put a small hole in the cap]
The durso can do a lot to quiet the tank side drain.