Bad bleach or bad test chemicals?

[volcano]

Currently setting up our "nanopool" for the season (10 ft x 30" Intex Prism). Currently filled to 22" with well water (no chlorine). Added 8oz of 6% bleach, which should bring it to 3.5 ppm (was targeting 5ppm but hadn't got there yet), but last year's Taylor-1003 test kit says I've only hit 0.5-1 ppm FC.

Two possibilities:
1. The bleach is bad. I picked it up at Lowes today-- I usually check date codes on bleach at the grocery store, but was trying to consolidate errand-running today. Code printed on the bottle: LO38002D and I have no idea what that means for date.

2. The reagents in the test kit have gone bad. The test kit sat in the garage over the winter, which means temps as low as -20˚F. I figured the reagents need to be replaced annually, anyway.

New test kit arrives in a few days. In the meantime, what's your guess: weak bleach, or useless test kit? I'd like to avoid anything growing in the pool in the next few days (although the filling water is a balmy 45˚F, so it's unlikely much will grow too quickly!).

 

[jseyfert3]

If I had to guess, I'd say that date code was the 2nd day of 2018. Meaning it's a year and a half old. I used to work at Lowe's, and I didn't buy bleach for our hot tub there (got it at Aldi or Walmart). Never saw people buying laundry supplies, and I worked as a cashier/customer service. Always seemed like an odd thing for a home improvement store to carry, honestly. If it's really a year and a half old it's no wonder it's got almost no strength left.

 

[volcano]

If I had to guess, I'd say that date code was the 2nd day of 2018. Meaning it's a year and a half old. I used to work at Lowe's, and I didn't buy bleach for our hot tub there (got it at Aldi or Walmart). Never saw people buying laundry supplies, and I worked as a cashier/customer service. Always seemed like an odd thing for a home improvement store to carry, honestly. If it's really a year and a half old it's no wonder it's got almost no strength left.

Thanks! Like I said, I don't normally buy bleach there, but was trying to consolidate some errand-running and thought I'd give it a try! Misguided attempt to be efficient. I'll add some fresh bleach today and see what the test kit says-- I'm still skeptical that year-old test chemicals (that likely got below freezing) will be accurate, but at least I'll get some fresh bleach in there and can calculate what FC should be until the new kit arrives.

 

[volcano]

Thought I'd update: the issue was definitely bad bleach. I added some fresh grocery store bleach and FC shot up to where it should be. Test kit results look reason, actually, but new kit will confirm. For now I'm relying on PoolMath to make sure I'm in the right target for FC.

 

[jseyfert3]

According to the Taylor manual that came with my K-2006 manual, so long as freezing did not force any reagent out of the bottle, they are thawed at room temp, there is no particles or suspended solids, or it has not discolored, it is fine to use even if it's been frozen.

The typical life of a reagent stored in cool temps is 2 years from manufacturing date. Depending where you order your regents, this may mean you might get two seasons of use out of them or may only get one.

Do they have an expiration date? (The ones in my K-2006 all have expiration dates)

 

[volcano]

Thanks @jseyfert3! That's really useful info from your Taylor manual. Expiration dates on the reagents vary from Oct 2019 to June 2020, so looks like I'm good for this year. Thanks for the help!