Ensure continued, reliable use of your Neptune Systems Trident Marine Aquarium Water Analyzer (LA# 112616) with a steady supply of Neptune Trident Reagents. Replacement 2-month Trident Reagent Kit (based on the default testing schedule of 4-Alk/2-Ca/2-Mg per day) includes two bottles of Reagent A (changed every month), one each of Reagent B and C (changed every two months), and one bottle of calibration seawater sample delivering at least 240 alkalinity tests and 120 tests each of calcium and magnesium. Reasonably-priced reagents average to about 9 cents per test!