Saves up to 50% of water changes – natural decomposition of water pollution. Natural microorganisms create clear, healthy, biologically active aquarium water. Eliminates ammonia and nitrite, reduces nitrate, neutralises food residues, breaks down mulm and sediment – prolongs filter maintenance intervals. Dosage: Fresh water 10 ml per 100 litres, weekly / Salt water 20 ml per 100 litres, weekly. Add a double dose after water changes, or 2 days after medication, in order to reactivate the biological filtration.