Say what you will... but these rocks rocked my world. I was super skeptical about what I thought was the equivalent to snake oil... but after using these rocks for several years now... hot spots on the lawn are a thing of the past.I would highlight that we continue to use these rocks in the winter to minimize saturation come spring...The product is fine, but I only got three packages of dog rocks, not 4 like I ordered!These work but I don't know why or how. Replace when they say.I love this chronic it was nice to lay of the rocks in the water and not worry about given him pills every day when it did work I noticed when they would stop using Them the grass got very spotty Brown love this productSeems to be working OK so farThis product is so easy to use. Plus, it works exactly like it is supposed toSo the only way these rocks work is if you don’t change your dogs water but every 3 DAYS!!! That’s disgusting!!! Definitly a waste of money