Just a related problem!
I just filled my pool on a sand base, and recessed 16" cement pavers under the legs of the ultraframe pool. Well, after about an hour when the pool is fully filled-two of the pavers broke in half.
Now I have the same problem because the side of the pool is sagging on that side. Looks like I will have to jack up the pool to replace the cement pavers with wood. I figured the cement blocks would last longer and be stronger than the wood.
So, perhaps everyone might consider using wood footings instead!