Taylor has started putting expiration dates on their reagent bottles. If your bottle was purchased in the last six months then it should have expiration date on it. If it only has a lot number on it, then it is actually older than 1-yr. You can call Taylor with the lot number and they can tell you the manufacturing date. If you purchased the reagent from a source online and it only has a lot id, it is entirely possible that they can sell you expired reagents. Only way to know for sure is to call Taylor.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006