lining aquarium bottom

what about a sheet of plexi glass? say 1/4"

 

yeah i wasn't sure if it was the cardboard like material. thanks that cleared it up.

i'm not really sure where i would get the plexi glass here, and i'm sure it would be expensive?

what about the styrotex panel that computers etc are packaged in? I have a lot of that. my only concern is if it's toxic or otherwise harmful? It would make a great cushion for the rocks and be very stable.

 

I wouldn't base a rock structure on something buoyant personally. People use starboard plastic a lot for the bottom of tanks. You might have to google it to track down a source though.

 

Buoyancy shouldn't be a problem. the are definitely heavy enough to keep it down. what about toxicity?

 

I don't know how thin/thick exactly the stuff that you're referring to is so maybe it really isn't as bad as I'm imagining but the rocks might weigh it down but the buoyancy will overall make them less stable as it will basically make the whole structure lighter because of the force constantly pushing up on everything. If you ever need to remove a rock for maintenance (lots of people do all the time) you would have to be careful not to upset the balance of weight vs buoyancy. Or what happens if you decide to reaquascape? It could be a big source of frustration.

I would also be concerned with the sturdiness of the material, you don't want bits of it breaking off, or being broken off by the critters in the tank and floating around and maybe getting clogged somewhere you don't want.

No clue about toxicity though, sorry.