QUOTE (dshnarw @ Dec 30 2008, 01:26 PM)

thats about right. 1/2" thick should be thick enough, no need for polishing as long as it's smooth on both sides.
styro would be fine for supporting the tank, but if there's concern about the irreversible sagging of the countertop, which is going to be the case, then you need the stone support as long as it reaches all the way between the vertical braces. the stone wont bend like the countertop, so all the weight will go into the vertical braces instead of the countertop itself, which is what is happening now.
But won't the trim/frame of the tank itself distribute the weight to the vertical braces, since the countertop supports are already under each end of the tank?
I don't think it's the weight of the current tank (the 20L) that is causing the slight dip in the countertop, I think it was the weight of the 5.5g that was previously setting there.
The countertop already had the the slight dip when I set the 20L on top of it.
Can you visualize what I'm talking about?
My dad works at Lowe's, I'm gonna call him and see what he can find there while he's at work today.