I am just in the process of setting up my 9 X 18 Hydro Force pool. I wanted the 9 x 18 Intex but was unable to track one down. For four years we had a 12 x 20 in this same spot but we never prepped it properly and I had a 3 in difference from side to side . We never filled it over 3/4 full to compensate..(strange logic I know ). Anyway this time I am doing it right. I have dug down the high side on the left where required (drain rock is for French drain) and have pretty much got it within an inch to an inch and a half side to side and end to end. I leveled a space 12 foot by 20 to make sure it had plenty of room. The sand has arrived and I will be moving it tonight to hopefully get the last last bit of leveling and softness for the liner.
I pre purchase a 3/4 HP Aqua something or another pump and sand filter to ensure head to the roof for the solar. I built my own with round tubes and it seems to work. I have the tree guys coming tomorrow to remove two big cedars and a fir that has needed to be removed for awhile. The prep on this to do it right is a lot of work and a lot of time. I know it will be worth it in the end!
Anyway here is pic #1 before the sand...