how flat does the surface under a glass tank need to be?

[miller44444]

I'm going to be setting up an all-glass 8-gal Fluval Nano Shrimp tank this weekend. The tank is going to be on top of a wooden filing cabinet. When I press on it hard, the top of the cabinet has a little bit of give in the middle, so I will need to lay a board on top to add a little more stability and make sure that the weight is more evenly distributed over the whole surface...However, the piece of plywood that I cut down to size isn't perfectly smooth, there are noticeable dips and bumps in the surface (maybe half a millimeter or so) that are caused by the different harnesses of the different growth patterns of the wood surface. I'm worried that if I use this piece, the shallow but wide dips in the wood are going to warp the bottom of the tank even using the thin foam pad that came with the tank. The other option is to buy a better board, and scramble to get it ready by the weekend.

Thanks in advance for your opinions!

 

[fort384]

With an 8 gallon tank, I don't think you will have any problems at all using the materials you have there on hand. you are only talking about 50-60lbs of pressure evenly spread over a few square feet. Almost nothing in the big scheme of things. When this matters more is when you start getting into bigger tanks in the 40+ range.