These test kits have passed their expiration date and are not guaranteed by Fresh Water Systems or the manufacturer. However, the test is likely still valid.
These calcium hardness test strips are used in the Sensafe Exact Micro 7 Photometer and in other water testing micro meters. Spa and swimming pool owners should test pool water for calcium regularly to ensure their hardness is in the proper range. Low calcium levels can result in corrosive water, which stains pool surfaces and destroys tile grouting and metal or plastic equipment. Likewise, if your pool water calcium level is too high and your water is too hard, scale can form on pool surfaces and in your pipes. High calcium hardness in pools can also lead to sore eyes.     Specifications:

• TESTS FOR: Calcium hardness
  
• Compatible with the eXact® Micro 7+ Pool/Spa KIT and other micro meters

Note: To ensure optimal performance, store your eXact kit in a cool, dry place away from excess heat (below 100°F/38°C), moisture, and oxidizers such as chlorine and bromine.