Water or motor noise? Water noise there's a lot of ways to baffle it start with raising the water level if it can be raised.

If it's motor noise check to see if it's oil filled because if it's not a new pump it probably will need a top off (food grade mineral oil or veggie oil is *usually* what they put in them but double check with the manufacturer though and make sure you're confident you can reseal it before you even open it).

If it's neither of these try unplugging it and plugging it back in breifly since it may have an air pocket.

Needs oil or air pockets was about the only two things I had go wrong with mine until it blew a seal. Now it only makes a bunch of noise (it's been demoted to water changes only). Might try checking the impellor too.

Adrea

What type/manuf. pump is it? Is it vibrating against something? Maybe just needs rubber mounting.

It's an Oceanic. I don't know much more about it...but I'll try to find out.

-andy

It's an Oceanic Sump3 system.
I think the rushing water noise is starting to get to them. Especially because they also just got a flat panel Plasma TV!

-andy

Okay here's three ideas if raising the water level doesn't work.

First one is to run a spraybar which will cut back on the splash but still make the water nice and aerated. Might have to go all around the tank before it really reduces any noise though.

Second idea get a bit of tubing that is big enough to go over the existing plumbing and allow air in. Bring the other end right to the water. This will make a cheapo venturi and cut back on a lot of splash noise. I do this on my ten in the back room.

Third idea is to put some batting or filter media where the water comes out. This one will be a pain to adjust with that much flow and will probably effect how aerated the water is.

Adrea

Can you describe the noise?

Brendan, I think the noise is more a function of the pump than anything else. The setup is a 180 gallon tank, and the pump they sold us is 2400gph. We went to South Shore Tropicals last night and James told us that the pump was too powerful for the setup. In fact, no motter how we orient the flow, there was always a hole in the gravel being blown by the returns. So...I think the thing to do is get a less powerful pump. Pump noise and vibration seem to be mitigated by foam rubber. Also, the back of the stand is wide-open...I guess to save money. So, we may block that up and use milk crate foam rubber to insulate a little bit more.

-andy