Penetraide Re-Wetting Granules. Rewetting Granules successfully main­tain an essential balance between water holding capacity and aeration of a potting mix or soil. This means that they will not waterlog a mix, they will actually improve the infiltration of water into the mixture and the drainage of excess water out of the mix.  An application of Rewetting Granules will also reduce your usage of applied fertiliser, as the granules help to elimi­nate water runoff.  Rewetting granules can be used at any time of the year, with no preferred sea­son of application. Simply re-apply them whenever you feel necessary, or every four to six months.