Gap between tank and stand, need a solution

[Ryan]

I would make sure the stand is actually level and square.

Had a member here have his tank bottom crack in half with the same set up. Wood bottom on the tank directly on the stand. Told by builder this was the way to do it. Turned out when they removed the tank, the stand wasn't square and level. Luckily they were home when it happened.

I know it will be a bunch of work, but I would pull the tank, throw a 6 foot level on the stand.
Left to Right
Front to Back
Corner to Corner

Builder can have all the warranty in the world, I still wouldn't want hundred of gallons on my floor, lost live stock, and a house remodel from water damage.

I think the wood will have give, but maybe a thin foam mat would remove slight inconsistency.

Let me ask, is this tank builder in Alberta? Calgary?

[hillegom]

I agree with you Shao
I would not want to put water in that tank until all of it is touching the stand.
I used a rubber similar to neoprene, wet suit material. Hard to compress with your fingers. It has holes in it like a sponge, but stronger.
Saw it on a work site and they were installing it between the windows and high rise. Comes in different widths and thicknesses.
I used it under my tank.
I know it will be a pain to instal, under the tank, heavy and awkward, but as target mentioned, "it will compress where needed."
Here is some info
https://canada.foambymail.com/neoprene-rubber.html
I would look for something like this
https://www.amazon.ca/Neoprene-Dualp.../dp/B07WZH14C5
but 1/4" thick by whatever width you need