API test kit expiry

[KLKelly]

Someone on another forum posted this.  They had contacted AP for a response:

Its right below the fl.oz on the front of the bottle.

In response to your question, each reagent bottle has a Lot # printed on the bottle. The last four digits are the month and year of manufacture. Example: Lot # 28A0102. This is a pH reagent manufactured in January of 2002. Pond Care Wide Range pH, Ammonia, High Range pH, Nitrate, Phosphate, Copper, Calcium and GH all last for three years. Nitrite and KH will last for four years. Freshwater pH(low range) and Pond Care Salt Level will last for five years. The expiration date is not a function of how often they are used or even when they are opened for the first time, but from the date of manufacture. I would not use or trust these kits after they have expired.