I apologize if this has already been posted; I did a few searches and suspect my keywords were insufficient.

At what point in time should you replace the old reagents in your test kit? My assumption is that, if kept enclosed at room temperature (68F-80F), they should be OK. I just want to make sure I'm not fooling myself in trusting results from 2-3 year old reagents.

Thanks!

Taylor says to replace all reagents each year. However, by and large the reagents will last several years if they are kept in a cool (not freezing) dark place. The FAS-DPD titrant and the organic dyes that provide the color in the PH, TA, and CH tests are the most sensitive. If you see one of the indicator dyes staining the plastic dropper bottle it has probably gone bad.

Thanks for the reply!

You can also take a look at Recognizing a Compromised Reagent from the Taylor Technologies website. I also wrote this post with rough guidelines for reagent life.