Mavea Carbonate Hardness Test Kit

This hardness test by Mavea is not only perfect for testing the total hardness in your tap water but also the effectiveness of filters such as Brita. 

Directions:
Fill the measuring tube with your tap water up to the 5 ml mark. Then add indicator solution drop-by-drop, gently mixing after each drop until the color changes from purple to yellow.

Protect your investment: test your water often.