Dog Rocks® are a coherent Rock with a mechanically stable framework meaning no significant mineral particles are released into the pet’s drinking water. In other words, Dog Rocks®do not break down or leech anything into the pet’s drinking water. Dog Rocks® provide a stable matrix and a micro-porous medium in which active components are able to act as a water purifying agent through ion exchange. So when placed in water, Dog Rocks® will help purify the water by removing some nitrates, ammonia and harmful trace elements thereby giving your dog a cleaner source of water and lowering the amount of nitrates found in their diet. This in turn lowers the amount that is expelled in their urine. An overload of nitrates in urine will cause lawns to burn. Dogs do produce nitrates as a by-product from the protein in their diet, but the difference between too much nitrate that will kill the grass and the amount of nitrate that will be good for the grass is very small.