Do supplements expire?

I just bought a new bottle of some supplementation only to discover I already had a bottle of the same stuff. But I don't know how old the other bottle is. I'm guessing a couple years....

Does that stuff go bad?

 

I just had to take an API test kit back because my readings didn't make sense, and the LFS said they think the product was dated.

Can you open the new box, test with the new kit and old kit, and if they match, take the new one back??

If we are only talking about 5-10 drops of solution, you should be fine to use once and then return.

 

Supplements are good for a long time if kept sealed tightly now test kits are a different story they will expire and not be worth a darn

 

some expire.i have reef plus that needs to be kept in the frigerator after opening.

 

Sorry, reading comprehension at an all-time low on that one!!!

 

Hello!

The supplements for reef growth can be easily oxidized by the oxygen found in the air. One should store them in cold/dark storage box or similar. Compounds like trace elements are normally used by reef organisms as so-called organic cofactors in many complicated biochemical reactions like e.g. reduction/oxidation, alikilation etc... In highly concentrated solutions they can auto-catalyze such reactions yielding new oragno-metalic compounds that can be highly toxic.

Cheers