Nickel sol'n; 1,000 ppm. Increases nickel in recirculating seawater systems. Increases primary productivity. Required by photoautotrophs (including zooxanthellae) for photosynthesis, pigment production, and nitrogen assimilation (particularly within systems dosed with urea and/or ammonium). 1 drop (0.05 mL) per 28.1 gal. (106.5 L), or 1 mL per 562.7 gal. (2,129.9 L), once daily to maintain NSW value for S=35. 1,000 ppm nickel, derived from nickel chloride (hydrated source, USP).