This is an all-in-one test kit from Red Sea which tests for Calcium, Alkalinity and Magnesium which are critical foundation elements in your reef tank.
The test kit includes:
75 Calcium tests
75 Alkalinity tests
60 Magnesium tests
Analytical grade glass vials
Easy-to-use, high precision Titrator
This test kit Reagent refills are inexpensive too & offered here.