Jonna, I don't think I would ever use perlite under water. Heck, 90% of what I use for my tropical plants (orchids in particular) would not be suitable in a situation as you describe. Why would you want to even use perlite or vermiculite under water?
drdawg (Dr. Kenneth Ramsey)
The reason it's so hard to lose weight when you get up in age is because your body and your fat have become good friends.
