Loud sump system

jake2342 · 2026-08-04T10:30:41-0400

I have recently set up my first reef tank with a sump. Everything is running well but it is very loud. I keep looking things up and getting different answers that don’t seem to help. Any suggestions?

Marco_99 · 2026-08-04T10:47:20-0400

Your flow adjustment on your overflow box and your main drain pipe are way too open and violent. That main pipe that’s like 12 inches long should be like an inch and a half under the water. The reason you have to run it that hard is because that pipe that deep in the water creates a pressure and takes a lot of water flow to push clear down that pipe when it’s submerged that deep. You would’ve been better suited with a gate valve there too instead of that shut off valve, but the shut off will work.

landlubber · 2026-08-04T10:49:31-0400

Is your return a DC pump? if so turn the return down until it quiets down. If you have an AC return it should have a ball valve between the return and the outlet into the tank that can be very slightly closed to slow the rate of return. If you don't have a ball valve and have a AC pump you should definitely add one.

jake2342 · 2026-08-04T10:51:26-0400

Marco_99 said:
Your flow adjustment on your overflow box and your main drain pipe are way too open and violent. That main pipe that’s like 12 inches long should be like an inch and a half under the water. The reason you have to run it that hard is because that pipe that deep in the water creates a pressure and takes a lot of water flow to push clear down that pipe when it’s submerged that deep. You would’ve been better suited with a gate valve there too instead of that shut off valve, but the shut off will work.

Everything came as a preset kit. Should I shorten the pipe or just keep slowly closing the valve till it’s quiet ?

mfinn · 2026-08-04T11:08:40-0400

When I hear problems with loud overflows or sumps the first thing that I think of, is how much water are you moving through it?
If the return pump is a dc controllable pump, dial it down.
If it's a ac pump, install a valve in the return line.
As far as getting multiple answers, any one single answer may not work, but using a combination of them may be the answer.

Marco_99 · 2026-08-04T11:13:13-0400

When you close that valve the water builds up in your overflow box and you can control how turbulent the water rushes out of your tank and down your overflow pipe. If you let water go through too fast it creates a waterfall noise. But in my experience when that pipe that I have the arrow pointed at is too deep into the water It takes a lot more flow/ to push the water down which in return creates lots of noise because you can’t let your overflow box build up enough water flow depth to get rid of the turbulence which creates the water noise. If you can get it all to work in silence without adjusting that pipe go for it. As stated above, your return pump also plays a part in it as to how much water you’re taking out of your sump and pushing up in to the main tank, that all has to create an equal balance with where your valve adjustment is and how much water you’re reserving in your overflow box to control the turbulence. It takes a lot of messing around to get a system dead silent, but it can be done. You just have to keep adjusting.