Do the testing agents have a shelf life?

[jkhamr]

Tested my salt level with Taylor R-0630 and R-0718 and the reading is 9,200 ppm. A couple weeks ago it was 3,200 ppm. No salt was added and my SWG is currently reading at 3,400 ppm. Do the testing chemicals have a shelf life? I'm not sure why there's such a spike in the salt level reading and why my SWG seems to be reading it correctly. We've had a ton of rain storms and plenty of debris blowing into the pool, but don't see how that would raise the level. TIA for any help.

 

[PoolStored]

Yes. I had reagent that expires in July this year and it showed my salt 200ppm above new reagents.

 

[Sunnydaze]

Some are more sensitive to time than others.

I have 3 year old reagents for the alkalinity test (R0007,8 and 9) and I just bought fresh reagents to replace them. I tested them against each other and the alkalinity test is exactly the same between the old and fresh reagents. I was surprised because i assumed the old ones wouldn't be giving me an accurate result anymore.

 

[JamesW]

Reagent Shelf Life.

All reagents have a shelf life, whether they are liquids, powders, crystals, tablets, or test-strip pads.

If kept dry, powders and crystals are very stable; acids are also long-lived.

Date of manufacture is not the controlling factor when it comes to shelf life—storage conditions are more important.

As with all perishables, reagents are sensitive to environmental influences and will last longer under controlled conditions.

To this end, we recommend:

Storing reagents at a consistent temperature in the range of 36°F–85°F (2°C–29°C); extreme temperature fluctuation, say from a refrigerator to a hot car trunk, causes reagents to deteriorate.

Keeping them out of prolonged direct sunlight. (Note: Brown plastic bottles help protect very light-sensitive reagents.)

Segregating reagents from containers of treatment chemicals.

Replacing caps immediately and tightening them carefully so exposure to air and humidity is limited.

Avoiding switching bottle caps, placing bottle caps on soiled surfaces, repouring reagents into contaminated containers, or touching test strip pads.

Taylor formulates its reagents to remain effective for at least one year, with only very few exceptions (molybdenum indicator in liquid form is one; after four months old it should be tested against a standard periodically).

As a general precaution, replace all reagents more than one year old, or at the beginning of a new testing season.

For all of these reasons we advise users to carefully consider the container size when purchasing reagents.

Larger bottles may appear to be the better value, but if you do not use them in a year’s time you may end up discarding reagent or risk exceeding the reagent’s useful life.

Taylor’s dropper tips dispense 25 drops per milliliter.

That means many tests requiring 5 drops of reagent per test will get 110 tests out of a .75 oz. bottle, or 300 tests out of a 2 oz. bottle.

Homeowners should consider purchasing .75 oz. reagent bottles, while service professionals should probably be using 2 oz. bottles.

Repouring from larger bottles (pints, quarts, or gallons) should be reserved for service companies with multiple technicians and retail stores doing high-volume testing.

When repouring, it is best practice to replace the reagent’s dropper tip after approximately 8 refills.

https://www.taylortechnologies.com/en/page/151/reagent-shelf-life

https://www.taylortechnologies.com/en/Image/GetDocument/588

 

[jkhamr]

Thanks for all the replies! I will order new reagents and see what the results are.

 

[JamesW]

Tested my salt level with Taylor R-0630 and R-0718 and the reading is 9,200 ppm.

Probably an error in procedure.

 

[JamesW]

 

[JamesW]

Most likely, you used a 25 ml sample instead of a 10 ml sample.

9,200/2.5 = 3,680 ppm.

For 1 drop = 200 ppm Sodium Chloride.

1. Rinse and fill 25 mL sample tube (#9198) to 10 mL mark with water to be tested.

2. Add 1 drop R-0630 Chromate Indicator. Swirl to mix. Sample will turn yellow.

3. AddR-0718 Silver Nitrate Reagent dropwise, swirling and counting after each drop, until color changes from yellow to a milky salmon (brick red).

 

[JamesW]

Use a 10 ml sample and multiply by 200 ppm.

 

[PoolStored]

Most likely, you used a 25 ml sample instead of a 10 ml sample.

Missed that, I agree...

 

[Newdude]

3 is me.

 

[jkhamr]

Ding, ding, ding, ding, we have a winner! Thanks for the observation JamesW, I indeed tested with 25ml not 10ml. Sometimes the obvious isn't so obvious.....

 

[Newdude]

Sometimes the obvious isn't so obvious.....

Fill 25 ml vial *brain shuts off* ......... to 10 ml. DOH !!!!!

Ask me how I know.

And Welcome to the bonehead club. Most everyone is a member and we meet on the 3rd Tuesday of every month to Welcome the new members.

 

[Desiato]

Some are more sensitive to time than others.

I have 3 year old reagents for the alkalinity test (R0007,8 and 9) and I just bought fresh reagents to replace them. I tested them against each other and the alkalinity test is exactly the same between the old and fresh reagents. I was surprised because i assumed the old ones wouldn't be giving me an accurate result anymore.

I just tested a R-0870 that has the date 09/22 with a new one and got exactly the same results despite the powder turning from white to grey. It has clearly degraded but I'm happy that it still works as these things aren't cheap over here in Europe. I will keep using the old one and once a month compare it to the new one to see if anything changes.

 

[jkhamr]

Fill 25 ml vial *brain shuts off* ......... to 10 ml. DOH !!!!!

Ask me how I know.

And Welcome to the bonehead club. Most everyone is a member and we meet on the 3rd Tuesday of every month to Welcome the new members.

I almost refered to myself as a "bonehead" in my previous response. Sounds like I'd fit right in those meetings.