Chemical Expiry Question - Salt Test

[shep377]

I got the Sodium Clor. test kit along with my TF100 last year, and I didn't use it all that much once I got the salt correct, it was just a once a month thing or less.

I did the test this spring (so the reagent would be about 8-10months old since I got it) and the milky colour of white for the salt test was fine, but when it turned red, I got a ton of tiny white solids particulate forming in the container. I can't for the life of me remember that happening to that extent. My reading is low - about 1800 (target 3200-3400).

Is this still normal or is perhaps the reagent old? I was hoping to go this season before replacing it all.

Cheers.

 

[BoDarville]

shep377:

The effective life of reagent depends largely on how/where it was stored. If it was stored inside the house in an enclosed cabinet or drawer (where I store mine) it should be good for at least 18 months, maybe even longer. However, if it was stored in the garage or a non-climate controlled shed then you may get only 12 months out of it. If it was routinely exposed to high amounts of heat and sunlight, it will go bad even sooner than that.

 

[shep377]

Well.. mine was stored in a box inside a closet in the house over the winter. Should be fine that way.

I just wanted to know if getting white chunkies (excuse the high-level technical jargon) was normal in my salmon colored milk solution with this test?

 

[BoDarville]

The salt test is the only test for which I use test strips. I also test salt levels monthly. Not having a SWG pool, I don't need the precision of the drop-based test.

Your storage method is sound, assuming the reagent was also stored the way you described during the summer when you first got it. When you first ran the test last year, do you remember seeing the white particles? If not, then I might get a little suspicious. Unless someone who uses the drop-based test chimes in as to whether the white solids is normal, the only way to know for sure is to purchase new reagent and run the test using that.

 

[CaOCl2]

the milky colour of white for the salt test was fine, but when it turned red, I got a ton of tiny white solids particulate forming in the container.

The silver nitrate you're adding dropwise is reacting with the sodium chloride (salt) and produces an insoluble precipitate of silver chloride. What you're seeing is normal.