This is a direct replacement to the old Nutrafin Waste Control. Fluval Waste Control A Biological Aquarium Cleaner helps decrease aquarium maintenance by reducing waste in gravel, power filters, decorative features and on interior aquarium surfaces. Waste Control\'s unique biological process rapidly digests organic waste resulting from overfeeding, fish waste and other decaying material such as plant leaves. Fluval Waste Control is especially beneficial for goldfish, cichlids, and heavily-populated aquariums where large amounts of fish waste are expected. During the course of rapid organic waste breakdown, ammonia levels may rise. The simultaneous use of Fluval Cycle Biological Aquarium Supplement is strongly recommended to control and prevent potential increased ammonia and nitrite levels, as well as to support optimal water quality and clean aquarium conditions. Size: 250ml (8.4 fl oz) Dosage: For new set-ups & maintenance: 5ml per 38 L (10 U.S. gal)* Repeat Every 7 Days for optimal aquarium maintenance.Waste build-up: INITIAL DOSAGE10ml per 38 L (10 U.S. gal)