Is there anything that can be used to hold the steps down inside the pool besides sand bags? Last year we had our bags of sand inside large ziploc type bags and they still leaked into the pool. I tried water bags (dumb I know, lol) but they kept floating up. Right now my dh has a huge rock sitting on the rack that goes across the bottom back side of the steps and I don't like it like that. What do you all use?