Spa chemical expiration?

[solo]

My neighbor owned a spa 4 years ago before moving to my neighborhood.  He has 2 bottles of HTH clarifier that were never opened.  I couldn't find an expiration dater.

He also had an antifoam product to get the foam out when it starts foaming, but that has been opened.

He also had an unoped botle of ph Stabilizer unopened.

I couldn't find an expiration on any of them.

He was cleaning out his garage and wanted to give them to me.

Thoughts and or advice?

[ndabunka]

Most chemicals are in a solid form.  Such chemicals generally retain their chemical composition as long as they remain in that state (solid).  If they are liquid-based, they can have some evaporation and thus could increase in concentration generated by water evaporation.  Just make certain they were for a spa and not a pool.  The chems are significantly different.  If in doubt, throw them out.  It's not like they are that expensive anyway $20 will buy you at least the smallest of any chem you might want to use.  If he had Di-Chlor, I'd snag all of it for use.

[TubsAndCues]

I've noticed that anti-foam can seperate after a few years, but if it is still sealed it should be ok.  One other thing I learned from my supplier (I sell BioGuard and SpaGuard brand chems) is that if any of the liquids freeze, they can seperate or lose their effectiveness.

Any chems that are solid should hold their value.

Test strips, however, do expire and they should have an expiration date on the bottle somewhere.  But, as  ndabunka said, if you aren't sure, toss them.