One pack of Dog Rocks in your dog's water bowl will keep your lawn in tip-top condition for up to 2 months. Please ensure that you have 1 whole pack of 200g Dog Rocks in each of your dog's water bowls (2 litres of water). It is important to let the rocks submerge in the water pitcher for 10 hours before use for them to be effective and the bowl must be filled with water at all times. One pack will last for 2 months and then must be changed to ensure continued results. If your pet really does not want a rock in its water bowl, you can put Dog Rocks in a jug of water and decant from the jug to the water bowl, it's that simple. Make sure your dog only drinks from water that has been filtered by Dog Rocks. Try to restrict them drinking on a regular basis from puddles, rivers, and streams. Bring water with you when your dog is away from home.