Tap water contains substances which are harmful to fish. Colombo Fish Protect detoxifies tap water making it safe for fish. Colombo Fish Protect contains 3 ingredients which remove toxic substances from the water; (1) EDTA (Ethylene Diamine Tetra Acetic Acid), the most important one, which chemically binds substances such as heavy metals, making it impossible for fish to take them up; (2) Colloids - long-chained molecules which can bind a wide range of substances including medicines and pesticides, as well as heavy metals, (3) CMC (Carboxy Methyl Cellulose) - this is originally a natural (cellulose) fibre, which is chemically altered to make it dissolve in water. Just as colloids, these long fibres bind different compounds like medicines, toxins and heavy metals. Dosage: When preparing water for new ponds and when carrying out water changes: use 15ml (1 cap) per 150 litres of tap water. For detoxification and stimulation of the mucus layer use 15ml (1cap) per 1,000 litres of pond water every fortnight. Ensure sufficient aeration and/or water circulation. 1,000ml Colombo Fish Protect prepares 10,000 litres of tap water and detoxifies / stimulates 7 x 10,000 litres