Strontium sol'n; 100,000 ppm. Increases strontium in recirculating seawater systems. 1 mL Isol8 Sr per 26.4 gallons (100 L) increases strontium by 1.00 ppm. 5 mL Isol8 Sr per 20.0 gallons (75.7 L) increases strontium by 6.60 ppm. 100,000 ppm strontium, derived from strontium chloride (anhydrous source, USP).