Test Kits Expire

[Coral Hind]

I just wanted to remind everyone that the test kits we use do expire so if you have had them for a few years you may want to check on the expiration date. For API each reagent bottle has a Lot # printed on it. The last four digits are the month and year of manufacture. Example: Lot # 28A0108. This is a pH reagent manufactured in January of 2008.

Pond Care Wide Range pH, ammonia, High Range pH, Nitrate, phosphate, Copper, calcium and GH all last for three years.
nitrite and KH will last for four years.
Freshwater pH(low range) and Pond Care Salt Level will last for five years.

I would not trust any kit after they have expired.

Liquid Nitrate Test Kits from any manufacturer can have a common problem with their last test solution. For some companies, it is bottle number 3, but for API it is bottle number 2. One of the ingredients wants to solidify out of liquid solution. If the test bottle sits for any period of time, this can happen. If this does happen and the test is performed without Bottle # 2 mixed properly, then you can get a falsely low reading. I have never heard of falsely high readings with Nitrate Kits. I would try tapping your Bottle # 2 a few times on a table or counter
top. This should loosen-up anything that has solidified. Then I would shake this bottle for about 2-3 minutes, to really mix it up. Try the test again and hopefully this will fix your problem. With regular weekly usage, this bottle should only need to be shaken for 30-60 seconds.

Always check results at the recommended duration of time. Letting the tubes sit longer can result in falsely high levels.

[modelboy213]

eek i never realized this. but i have a question my API nitrite/nitrate test strips are marked
M7194
04/2009

But i bought them like March 2009... but they're still expired. ..

[Coral Hind]

The date shown on the lot # is the date they were made. So they would be good for at least three years after that date.

[modelboy213]

OK good cuz i was about to mad i bought expired stuff! lol