The Neptune Systems Trident Reagent Kit is a 2-month supply if you assume the default testing schedule of 4-Alk/2-Ca/2-Mg per day). The reagent kit has at least 240 alkalinity tests and 120 tests each of Calcium and Magnesium.
Kits includes:
Two bottles of Reagent A (changed every month)
One bottle of Reagent B (changed every two months)
One bottle of Reagent C (changed every two months)