rocks -- heavy rocks

tedr108

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Nov 21, 2007
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Another newbie question...

I am in processing of collecting decor for my tank. The only free rocks (and I need free right now) I have available to me are granite. They look decent, but I am concerned about the weight. They are not boulders, but I could end up with 20 - 30# of rocks easily, since granite isn't exactly light. So, my question is: Since the tank frame lifts the bottom glass up from touching my stand's top surface, isn't it possible that the rocks could crack the bottom glass? Should I try to find some sort of rubber mat or something and cut it to fit just under the tank?

My tank is only 36x15x16 and the glass is 1/4" thick, as far as I can tell.

Thank you for your time...
 

VaughnH

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Jan 24, 2005
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Unless you are planning to nearly fill the tank with rocks it isn't likely that they will damage the tank. Their weight is reduced by the rock volume in water - a half cubic foot rock will push on the glass with its weight minus the weight of a half cubic foot of water (31 pounds). However I suggest you not drop a rock in the tank, just gently place it in position. I use granite rocks in my 45 gallon tank, with no problems.
 

Tom Barr

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Jan 23, 2005
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you can also use a styrofoam pad under the sediment.

But adding it after the tank is set up?
Bit of an issue..........

Regards,
Tom Barr