help me use this product

[Johnny B]

Can you help me use this product ?

Neighbor gave me some free stuff , called Pool Shock by In The Swim
Calcium Hypochlorite 68%
Other ingredients 32%

A 1 lb bag will raise 10,000 gal 5-10ppm

I can follow the FC ppm, but I assume it has CYA as the " Other ingredients 32%". How much? I add CYA to my pool 3-4x per season so I'm not opposed to adding it via this method so long as I don’t add too much. My pool does best at CYA 40-50 (and TA of 50 summertime, so both those are a bit weird but this is fact after several seasons), so I always Target CYA 40 which is where it is now. but we get plenty rain, evaporation + tap water added etc

I will take that 1lb bag & convert it to dry volume & go from there. Also the 1st time I use it I will test my FC before and after adding the product to see how it performs on the FC ("5-10ppm" is a pretty huge range)

I got enough free bags to last me a lifetime, so next question is there a shelf life because I see none.

Not leaving BBB, just using free stuff for the occasional CYA & of course while that’s going in I get some FC. Newbies still learning: ignore this post for now if you don’t understand .
Thanks

 

[justinc]

The other ingredients are probably buffers/fillers/impurities in processing. The issue with cal hypo is not CYA. It's calcium. What is your calcium hardness? If you are too high, it will add more calcium...

It will last you years but if your your water is hard or you have high calcium hardness already best to avoid. Very stable shelf life. Like i said..years.

 

[Johnny B]

Thanks . Ah, yes, of course you are right, I was thinking of another product (a puck?) that adds CYA. And I see that sentence on Pool Math in the FC section re all this. Yes it adds calcium to raise CH, which I have to do to winterize, so I'll keep it for that.

How much will this product raise my CH?

Secondly, I'll give it to a neighbor who doesn't BBB. Are there any pools where this product is not indicated? Is it ok for liner pools etc ?
Thanks again

 

[justinc]

It usually comes in 1 pound bag. In 19,800 gallons, 1 pound of calcium hypochlorite 65% will raise FC by 3.9 and raise CH by 2.8

It is fine in any pool type that doesn't have issues with excessive calcium.

 

[mariane]

Do you know how much cya is in cal-hypo?
EDIT:
Found it on web search: says 0, no cya in cal-hypo. I was thinking the same thing as OP to use it to increase cya. Guess the answer is: nope, won't help.

 

[Johnny B]

Justinc: " It usually comes in 1 pound bag. In 19,800 gallons, 1 pound of calcium hypochlorite 65% will raise FC by 3.9 and raise CH by 2.8"

Thanks. I believe you, but how do you know, is there a formula, or I am missing it somewhere on PoolMath?

So I can use these pretty much all summer, just keep an eye that I don’t get my CH too high. My summer CH is 300 & winter is 350-400. Great news. When I use it I will take a 1 hour test of FC just to be sure.

And I want to be sure I understand you, if my CH is 300, a 1lb bag will raise my CH merely to about 302.8?
Thank you

 

[justinc]

Use PoolMath "effects of adding chemicals" 16 oz of calcium hypochlorite at 65% and it will calculate it for you based on 19,800 gallons (or whatever # of gallons you enter).

And yes, if you are currently at 300 and you add 1 bag, you'll now be at 302.8... and so on and so forth...

 

[Johnny B]

Thank you very much , I missed that very handy section on Pool Math. Conveniently my 16oz (1lb bag) is 15oz by volume , close enough to a direct 1:1 ratio weight to volume for what I'm doing, making calculations easy.