Anyone use them ? Cubes will protect your pool from lotions, ammonia, and chloramines. It’s lotions that I like. With young kids today swimming- all the moms load up there kids with sun blocker. Yesterday we had 12 kids from 3 to 11 years old. I was sitting down having coffee and watched all the moms loading up the kids with lotions. I do keep a tennis ball in each skimmer, by the end of day I can grease my car with all that I removed from the balls. Lots of that grease gets into my filter.