I would ask at the LFS to see if he can get some baserock for you. I know that you can purchase it at certian hardware stores (it's intended for other purposes, but its essentially the same thing, and way cheaper) so you may want to look around there too. the reason you mentioned would be the only reason that i'd worry about the ceramic. worst case scenario i'll go pick up some base rock and mail it to ya

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Andy
My 29 Gallon Reef! My DIY LED Lights Current Status - Camping - Back 7/21/08
I'm still around people, just on a sort of "summer-time leave"

Feel free to PM or e-mail me for any needs!