Salifert Strontium Profi-Test In a marine aquarium strontium plays an important role in accelerating the growth of coral and calcareous algae and natural sea water contains approx. 7 - 9 mg/L strontium. Strontium is very difficult to test for, but if there is found to be a depletion of calcium in the aquarium then strontium levels are likely to be very low as well. It is advisable to maintain a strontium concentration of between 5 and 20 mg/L. Salifert was the first to introduce a strontium test kit and this test measures both ionically free and moderately complex strontium in increments of 5 mg/L. Sufficient for up to 40 tests. For marine use only. Warning!Reagent Sr-1 is caustic. In case of contact with eyes rinse immediately with plenty of water and contact a physician immediately. In case of ingestion do not induce vomiting but contact a physician immediately. In case of contact with skin wash with plenty of water. Keep out of reach of children.Instructions:1. Fill test vial with 5ml of water (use 5ml syringe).2. Add 12 drops Sr-1 (caution caustic) and swirl gently for 10 seconds.3. Add 1 level scoop of Sr-2 and swirl gently for 5 seconds. The color should be red/pink.4. Fit the 1ml syringe without the yellow label with the small plastic tip. Ensure that the tip is mounted firmly. Fill this syringe with 1ml of Sr-3 (lower end of black rubber ring at 1.00ml mark). Dose this amount in the test vial and swirl gently for 20 seconds. If the color has changed to blue and remains so even after an additional 30 seconds then the calcium concentration is far too low (approx. 300mg/l or less) and should be corrected first before doing strontium testing.5. Again fill this syringe with 1ml of Sr-3. Add this drop wise to the test vial. Swirl gently for a few seconds after each drop until the color changes to blue. If the color has changed to blue then swirl gently for 15 seconds. It is very likely that the color will revert back and will not be pure