Slate tiles

[Eric]

I am thinking about using large slate tiles as a background inside a new tank. 
Has anyone done this, or is there any reason not to? 
Do you think there would be a problem with the lack of circulation behind the tile -- I don't really want to to use a mess of silicone to fix it permanently.
Eric 

[darkdep]

I did this on a 90Gallon before.  I used pieces of broken up slate, some of which specifically came from tiles.

What I did was create a rectangle matching the size of the back of the tank on my floor with painters tape, then played jigsaw puzzle with the rock until I had it looking good.  I broke up some extra pieces to get smaller bits to fill in the cracks.  One thing I didn't do but wish I had was to cover the back of the tank in something black (tape on background, paint, felt, etc) so that the cracks look like dark little caves.

It looked great, and once some algae started growing it looked very natural.

Disadvantages:  Don't even THINK about trying to remove it once you've applied it.  I wouldn't recommend this for any tank made with thin glass, as the slate is heavy...only do it if you're sure the tank is not going anywhere for a long time. 

[beowulf]

As mention sort of by DD my biggest worry would be breaking the glass as the tiles would end up being very heavy.  The other thing is you lose a small amount of volume in the tank.

[darkdep]

For my tank, I used eggcrate on the bottom, then sat the bottom layer sitting there while drying, once dry I added the next layer, etc etc.  It worked out well and I saw no signs of problems, but that being said a 90gal has much thicker glass than a 75 or smaller, so I would recommend at least a tank with glass of that thickness (I think a 90 has 1/2" glass?)

[Eric]

Thanks.  Sounds like I should weigh them up.  I saw some 18 x 18 natural slate tiles.  I was thinking of just standing them up with rocks in front anb maybe a gob of silicone at the top.  I don't really want them permanent because I change my mind every 5 minutes 

This reminds me of another question, do you think eggcrate or styrofoam is better for rockwork -- assuming I need something under there? 

Eric