How to tell if test liquids are out of date?

[malawinovice]

I have some API test vials and liquids.

It is about 15 months old. Do these things have a way to see if outdated?

I have heard you should keep them only for a year, but how long has it been sitting on the store shelf?


ideas?

[Racing1]

API kits are not that reliable and I am sure they are out of date. There should be an expiration date on the box. If you are going to pick up new kits I would recommend Salifert.

[DrBegalke]

API kits are reliable, they just don't have the precision of the more expensive kits like Salifert.