Manganese sol'n; 5,000 mg/L. Increases manganese in recirculating seawater systems. Increases primary productivity.  Required by photoautotrophs (including zooxanthellae) for photosynthesis, pigment production, reduction of nitrite and nitrate, antioxidant activity.  1 drop (0.05 mL) per 234.9 gal. (889.2 L), or 1 mL per 4,698.5 gal. (17,783.8 L), to establish NSW value for S=35 @ 77°F.  5,000 mg/L manganese, derived from sulfate- and/or chloride salts of manganese (hydrated source, USP).