Hermit Crabs require a dish of freshwater available at all times. This conditioner conditions tap water into safe drinking / soaking water for your crab. Add 4 teaspoon of conditioner to each cup 8 fl. oz. of water. Measure amount of water in your crab's water dish and adjust dosage drops accordingly. Use every time water is changed. This Product/Package Measures: 1.40 in. L x4.20 in W x1.40 in D