I'm uncertain about the brand of pool filter sand. I purchased it at a
swimming pool supply store. If you plant densly enough you'll never see the
sand.
The kitty litter is the WalMart brand "Special Kitty" in the red bag,
unscented.

The bottom layer of kitty litter is great as long as you don't disturb it by
uprooting plants constantly.

I'm rather keen on the Flourite.

N8 Goetz