[SueM]

Yes, I've used the sand type. It is the same basic chemistry, but I prefer the
look of the larger type, and I think it gives better circulation to the plant roots.
xerxeswasachump, you can try a diatom filter, but you may consider taking it down and
rinsing the heck out of it, other wise every time you touch it, replant or vacuum you get
a super cloudy tank, I put mine in a 5 gal bucket, put a hose in the bottom full
blast, stirring it once in awhile, then let it run till the water is clear.
I use 100% fluorite, and since I started doing that, I've never had a cloudy tank.