Trashed the Bio-Balls.

[Loverotties]

No go under the water level so no noise or splash.

[Kakalakasha]

Originally Posted by Loverotties

No go under the water level so no noise or splash.

Oh!
Good point.
So that should cover the sound of the splashing into the sump.
But what about the suction sound the overflow makes when it takes the water down to the sump?

[chrisd]

can you post a picture of your overflow?

[Kakalakasha]

Originally Posted by chrisd

can you post a picture of your overflow?

I sure can.
But it is a hang on the back overflow.
It's got the black part with the little cut outs on it, in the inside of the tank and the clear part where the U-Tube brings the water.
Then the clear part has a hole which drains down the the sump, obviously gravity driven.