Waterwise storage crystals. When added to potting mix or garden soil, the crystals absorb up to 400 times their own weight in water. This water is then released back to the plants over time as they require it. The crystals reduce water wastage, increase the time between waterings and promote improved plant survival during dry times. The crystals are effective for up to 5 years, then biodegrade harmlessly.Featurescan be used in both potted plants and garden beds, to store water and to keep plants healthy. Water storage crystals prevent the soil drying out, improve soil aeration and drainage.Water crystals rehydrate themselves with each watering, lasting several years before biodegrading harmlessly.Using water storage crystals, plants can tolerate drier weather conditions and less frequent watering.Ingredients potassium based.