Austin's pool tech shock (liquid chlorine) 12.5% 18095 (04/04/2018). Today 5.5%

[nikon5400]

Just tested my almost 14m old chlorine by adding it to the pool. It looks like it's about 5.5% (had 3.5ppm, added one gallon, now 60-90 min later 6ppm). Water temp 68.
Used last year's 870 and 871 for the test.

I keep chlorine in the basement, where the temperature is probably below 70s most of the year, may be warmer in the winter.
I purchased it from Leslie's, where they keep it in the backroom with no air conditioner and it felt like temperature is way above 70. Don't remember when I purchased it, but I think it was around August (price was good, I decided to take it)


I talked to Austin's a few years ago, they said it'll lose about 10% every month if kept below 70 or 60, don't remember. so I expected it to be around 3%, but not 5.5%.

 

[nikon5400]

I retested this 14m old 12.5% chlorine twice since Monday. It is 5.5%.

So, my thinking is - if 12.5% is on sale for a price of 6-8% and there's a way to keep it in a cool place, it's worth stocking up for a season (4-5 months in my case)

 

[Catanzaro]

Interesting topic. The pool shock that we purchased in NJ either comes from Austin's or another company (do not remember). I am almost convinced that it is stronger than 12.5% for a month or so, but not 100% convinced. For me, I only purchased (now on Salt, but still use Liquid), enough for 2-4months at most. I would not purchase more than 4 months. From what I can tell, the bleach will come down to about 10%, even after 2-4 months. It is easier for me as having only one trip is more economical.

What it comes down to is that the price of $3 per gallon is worth not even bothering shopping around. There is a degradation schedule (Credit given to Chem Geek) that you can look at.

Degradation Schedule (Chem-Geek)

http://www.troublefreepool.com/threads/60837-Breakdown-of-bleach-over-time-by-storage-temperature?p=725315&viewfull=1#post725315

 

[getreal720]

Interesting... I plan to stock up (not on this brand, but another similar product) if I can find it locally.... I was going to buy what amounts to 3 months worth (as my swim season isn't much longer than that). So I can plan on the stuff being just under 10% by the time my 3 months is up (or likely a little higher).

Still it's nice to just get it in one haul and be done with it. Plus having 20 or so higher strength bottles is nicer than having 50 of the "regular bleach" bottles.

 

[an1vrsy]

For my liquid chlorine use, the pool store is 2 miles away. My pool consumes 4 gallons every 2 weeks during this time of year. So, I drive over and pick up another four 1 gallon 12.5% jugs then. Because they also service pools in my area they constantly get new shipments from Hasa bi-weekly. So what I dose (44 oz) on a daily basis is consistent with my expectations (pool math) and confirmed with my K-2006C.

 

[nikon5400]

I guess it matches up (somewhat) with the table below (on the bottom of this page) My 12.5% chlorine was about 415-420 days old, but temperature in the basement is below 70, probably around 65-67

 

[jeffr47]

How did you work out the actual concentration? Just worked backwards from the change in PPM for a known volume?

 

[nikon5400]

How did you work out the actual concentration? Just worked backwards from the change in PPM for a known volume?

Yes. I used pool math calculator
I didn't know the concentration, so I added 1 gallon and tested water an hour or two later using agents 870 and 871. Then I put the result in target field and kept changing the percentage until I got 1 gallon

By the way, just checked my basement temperature - 65.5 on the top of the box, 64.5 on the floor (tile), 63 in the room where ac air handler is. I wonder if it makes sense to take bottles out of the boxes and put them on the floor