Styrofoam thickness under tank? I am not sure if this is in the right forum for this question. I posted this on RC as well. I am not sure how many rimless tanks are here in the BRS. I ordered a custom 205 gallon tank (51X37X25) and I am curious as to what size Styrofoam to put under the rimless tank. Lowe’s has ½ 4X8 sheets. Is this enough as I would like to hide the foam with a piece of ¾ trim.