Do test kits go bad? How do you know?

[Newt]

I just finished testing the water in my 75 gallon. Everything checks out fine, but it made me think about the shelf life of test kit reagents.

Do they go bad and how can you tell?

 

[WyldFya]

Depends on the reagents used. If they are the API tests, then there will be a serial number stamped on the box somewhere. The last 4 numbers of that serial are the 2 digit month and 2 digit year. API reagents last ~3 years.

 

[davo]

I tend to run out before they are likely to go off anyway....
Sometimes you'll be lucky enough to have a "best before" date.