The HI774 Ultra Low Range Phosphate Checker® is a cost-effective way to measure phosphate in marine systems, including reef tanks. Excessive phosphate levels can prevent calcification, skeletal formation, and growth of many coral species. The HI774 Phosphate ULR checker provides an accurate way to measure phosphate from 0.00 to 0.90 ppm. Easier to use and more accurate than chemical test kits, it features auto shut-off, large easy-to-read digits, and is designed to work with HANNA's reagents.