Nutrafin Betta Enviro-Clean 60 mL (2 fl oz), is a betta bowl cleaner that biologically breaks down waste in betta bowls and containers while promoting clean conditions that help reduce diseases. DOSAGE: Shake well before using. 2.5 mL (approx. capful) treats 3.78 L (1 U.S. gal / 0.83 U.K. gal) with every water change.