what media to use ???

[xahx]

I have a built in over flow in my 60 gal saltwater tank,

I cant find an efficient media to put in the overflow so the tank doesnt have that "gurgle/slurp" sound when it drains to the sump... Can any one suggest any media that i can use to eliminate the sound and get the best biological filtration out of?

What are your opinions about "bio balls'' for saltwater reef tank?

Thanks All suggestions comments concerns welcome!

[TCTFish]

I don't think bio balls are needed in a reef. The live rock and sand will give you enough filtration. Won't really hurt anything so long as it is kept free of debris build up. They can be "washed" with used aquarium water.

Is the overflow box built in or HOB?