The simple way to keep your above ground pool step weighted down. Each Anchor Universal Pool Step Weight by Main Access holds up to 50lbs of sand and is made from Pool Chemical Resistant Commercial Grade plastic.
I bought these before from another source and they lasted for 2 seasons. After the second season, a number of the handles broke and part of the bottom broke out of one. I used river stones (no sharp edges) for weights rather than sand since I didn't want a huge mess if they broke while in the pool. They did perform as expected, but I thought they would be more durable. E-Z Test Pool Supplies offered the best deal I found on the internet for these and I ordered 5 replacements from them. They arrived very quickly and in good shape.