View Full Version : Expiration date on KH test solutions

07/17/2010, 04:47 PM
I have 3 different bottles of KH test solution for measuring the carbonate hardness (alkalinity level.) The brand is not shown, but I am figuring that the LOT number must involve the date. I dunnofor sure but I suspect its in the form of XXXMOYR. I have three bottles with lot codes of:

59A1008 (written in black)
59A0408 (written in black)
59A0109 (written in yellow)

Guessing Oct '08, April '08, Jan '09....

The three give radically different hardness measurements. I am guessing I should toss the two old ones, but how long are they to be used ?

Pic sucks, but you can probably recognize the brand.


07/17/2010, 05:07 PM
That's going to be hard to guess with any confidence. I'd ask the manufacturer, if possible at all.

07/18/2010, 05:06 PM
pretty sure you are correct on the dates that API use but i think that is the date of manufacture and can be used up too 1 year after that.