Yes. There is some sand under the base. I decided to drain it and discovered that it couldn't be level because there was more water at one end. I checked to see if it was still level after it was emptied and it was level at the end where the water pooled and slightly off on the opposite end and slightly off on the sides. I don't understand why it was level when it was 1/2 full of water and not after draining all the water out. Every time I checked the pool level I had another person help me. We placed the level on each rail when we checked it when it was empty but it looked off. We tried another method to check the level. We placed the level in the middle for each side and tied a string to one corner and used a little level that hangs on the string and tied to opposite corner and repeated the same process for the other three corners and the sides. We decided to buy concrete pavers to support the legs and will make sure they are level with the ground and try it again. Is there a better way to check to see if the pool is level? I must be doing something wrong. Thank you for taking the time to assist me.