Tank shimming advice

[digital-audiophile]

OK, So I am one step closer to getting my growout tank set up. A fellow board member (thanks Neil!) built me a stand for the tank as I have very little DIY skills.

I moved the stand into my utility room where I have my sump and since the floor slopes towards the drain from where the tank is sitting I have a 3/4" gap from the floor to the bottom of the stand at it's highest point.

Now I guess my question is: is this too extreme of a shim, or is it safe if I do it properly and then the next question is what is the best/safest way to shim the stand.

Thanks in advance for your help fellas (and ladies )