Kitty litter or sand for 1st chamber dsb?

I'm no expert about clay.... but clay is just silt laid down with lots of minerals and what not from watery places. Sand is sand... any type of mud is sand with clay. The sea floor has lots of clay and mud in it's make up... it is not just sand.

Miracle muds and what not are marketed as some miracle trace element replenisher. The thinking is that these trace elements are slowly leached into the water column and replace what is lost. Clay of any kind... grey Georgia clay used for Kitty litter is rich in minerals and trace elements.

Kitty litter has been used by many with out problems. I actually could not find any plain litter in my area and decided against it. All I could find was unscented and what not but said anti microbial so I said no. Any way it is easy to find for most.

Having said all that nobody can test for trace elements, nobody can say what the depletion rates are in a aquarium, and nobody can say what are the replenishing rates of mud in DSBs. Even though most that use clay or muds say they become depleted and must be replaced every year.... sorry, I,m not going to tear out my DSB every year to replace some miracle mud that is worth it's weight in Gold.

I did put down some mud in my fuge, but had no plans to replace it soon. The most IMPORTANT part of a DSB in fuges isn't any ole sand... it is fine "oolitic" sand. That is very important for critters that inhabit the sand bed. They need a specific particle size to move around. A very good article is here:

How Sandbeds REALLY Work by Ronald L. Shimek, Ph.D. - Reefkeeping.com