How concrete are reagent epiration dates?

[Nor'easter Reefer]

Picked these up for 75$ a week or so back. Just getting ready to try them out and verify they work properly, and I noticed the phosphate tester reagent expired 11/2023. What are the odds that the expiration date is similar to most things nowadays and it's probably fine? Quite a decent chunk of reagents to throw away and plus, i want to try it and see if it works :winking-face-with-tongue:

 

[Nor'easter Reefer]

 

[EeyoreIsMySpiritAnimal]

I doubt it's fine... buy new reagents.

 

[Nor'easter Reefer]

I doubt it's fine... buy new reagents.

That's what I assumed but thought it was worth a shot. :upside-down-face:

 

[braaap]

If they didn’t get wet then I’m sure they are fine. I’ve had some 2-3 years expired. Compared them against brand new and got identical results.

 

[Nor'easter Reefer]

If they didn’t get wet then I’m sure they are fine. I’ve had some 2-3 years expired. Compared them against brand new and got identical results.

I already ordered some new ones. When they arrive I'll compare a few and confirm as well.

 

[taricha]

I trust packets to hold up longer than liquid reagents generally, but I wouldn't be confident enough in the Ca, PO4, or NO3 stability past expiration to override my concern that I might just be wasting my time.

I already ordered some new ones. When they arrive I'll compare a few and confirm as well.

I am interested in these results though. Thanks!

 

[Waters]

I agree they are probably fine but the one time you test and get a result you aren't expecting (or wanting) you are going to question the reagents so they probably aren't worth using.

 

[gbroadbridge]

I agree they are probably fine but the one time you test and get a result you aren't expecting (or wanting) you are going to question the reagents so they probably aren't worth using.

But that can happen with brand new reagents too :)

Hanna nitrate has done that to me many times, phosphate not so much.

 

[Waters]

But that can happen with brand new reagents too :)

Hanna nitrate has done that to me many times, phosphate not so much.

I personally have never had to question new reagents but you are correct....it definitely can happen.....much more likely with expired ones though lol.

 

[Nor'easter Reefer]

I am interested in these results though. Thanks!

 

[Dan_P]

Picked these up for 75$ a week or so back. Just getting ready to try them out and verify they work properly, and I noticed the phosphate tester reagent expired 11/2023. What are the odds that the expiration date is similar to most things nowadays and it's probably fine? Quite a decent chunk of reagents to throw away and plus, i want to try it and see if it works :winking-face-with-tongue:

Easy enough to check before throwing them out: compare their performance to new reagents.

 

[Dom]

That's what I assumed but thought it was worth a shot. :upside-down-face:

You could always double check the test with expired reagent to the new reagent.

 

[JayM]

Not very concrete. It’s very dependent on storage conditions. Reagents stored in high temps and/or high humidity may not be any good before the expiration date, stored cool and dry may be good long after.

 

[vetteguy53081]

Ive tested 3 month old packets with new ones and were almost a match. Hanna says refrigerating them buys extra life ( not sure if true but I am trying it)

 

[Miami Reef]

I predict the old reagents will test the same as the new ones. Please keep us updated. I’m very curious.

 

[Nor'easter Reefer]

Ive tested 3 month old packets with new ones and were almost a match. Hanna says refrigerating them buys extra life ( not sure if true but I am trying it)

I didnt know that. I heard people claiming that keeping the reagent with the unit can cause issues? And that the vials should be stored with rodi water in them. Which I didn't know and was at first, very confused as to why the vials had water in them when I bought them used.

 

[Nor'easter Reefer]

I predict the old reagents will test the same as the new ones. Please keep us updated. I’m very curious.

New ones just shipped today. Don't have a arrival date but I'll post results here when they come in

 

[vetteguy53081]

I didnt know that. I heard people claiming that keeping the reagent with the unit can cause issues? And that the vials should be stored with rodi water in them. Which I didn't know and was at first, very confused as to why the vials had water in them when I bought them used.

yes, the vials if scratched or dirty can give false readings.

 

[Nor'easter Reefer]

yes, the vials if scratched or dirty can give false readings.

At least today wasn't a waste. I learned something :beaming-face-with-smiling-eyes: it makes sense though.