Foam under a SeaStar tank?

[Borderjumper]

My tank just cracked. The bottom cracked from one corner length wise in a big S all the way to the opposite corner.. For the full 4 feet.

This is.. Well was.. A 18 month old 4ftx2ft old Sea Star tank made with 1/2" glass.

We put a piece of pink insulating foam under the tank.

We just took the tank off of the stand and it looks like the edges of the tank compressed the foam slightly.

What Im wondering..if the edges compress, this is basically lowering the bottom glass until it contacts the foam. This foam is pretty rigid. I'm thinking that with the edges compressing, more pressure was being put on glass.

Looking at the bottom of the tank, it looks like the frame is slightly higher than the glass bottom.. But only a fraction.. I'm thinking the tank is made so that the edges carry all the weight and the bottom basically "floats" for a better word..

So if the glass is supposed to float, with no pressure on it from the stand are we screwing this up by letting the tank sink into the foam causing the bottom to make contact, which makes it suddenly bear weight?

Thoughts? And does anyone know if a seastar tank is designed so that only the frame carries weight? I remember tanks from when I was a kid.. They used to sit on those old metal stands that were only frames with nothing in the middle.