Need 2nd Opinion on % vs Volume vs $ calculation/assumptuion

[aylad]

This is bordering on China Shop material......the OP is satisfied with the information that he has. So if y'all want to continue the debate, please take it to the Shop!!

Janet

[CarlD]

Of course you are right.

Carl

[Sponge1971]

This is bordering on China Shop material......the OP is satisfied with the information that he has. So if y'all want to continue the debate, please take it to the Shop!!

Janet

- Does OP mean Original Poster? (just a wild guess...)

- I don't want to propogate any flaming but I do have more data to add to the whole purpose of this thread: to determine the most cost (and convenience) effective way to chlorinate my pool...ultimately anybody's pool. Briefly: I bought a 2.85liter jug of Walmart 4% for $1 !!! That's better than the original 5liters for $2. I'm going to 'Carl Test' it and compare it's $/ppm to the other's here... (I also sourced 7kg of 62% CalHypo, for ~$87...wow! that's steep, but massive Chlorine content...)

- I feel this discussion is valid to this master 'chlorine' thread, because (once this testing discrepancy can be settled) it will lead to a simple and cost effective method for 'poolies' to source their chlorine...and isn't that a cornerstone for BBB? 'simple' & 'cost effective'. If I may suggest...the future result of this discussion should result in an infromative, well written, descriptive 'sticky' for all poolies to find at the front of the 'cholrine' master thread. I'm certainly don't have the credentials...but I'm not totally helpless...and if anything, I cal play the roll of the layman lab rat.

- I'm just a FNG here, so let me know if I'm stepping out of line...but either way, I still appreciate the discussions we're having on the few threads I've posted to. My work mate 'poolies' just sigh and ask "who cares?!?" when I start discussing this thread. My BFF doesn't even test his pool anymore...he just backflushes, shocks and chucks in his weekly concoction. Ok...maybe that works...but it's certainly not the 'best way' to go. I appreciate yous guys are passionate about doing it the 'best way'...in the spirit of BBB. They look at me, like I have three heads, when I mention BBB to Them...that pretty much squahses any interesting/dynamic coffee break discussion.

[giroup01]

2,85L of 4% at $1/Liter = $0,09/ppm
7000g of 62% at $87 = $0,2/ppm

You would think the $1 bleach is quite inexpensive, but it's actually twice as expensive as the cal hypo from Trevi or the 65% stuff at Club Piscine.

The Costco HTH cal hypo, 22,7 kg for $94,99 is even more expensive at $0,06/ppm. You'd think they would be the cheapest.

[Sponge1971]

giroup01,

How are you coming up with X% of Yliters = $Z/ppm?

Is there some constant to describe how much ppmFC there is per %SodHyp?

[giroup01]

giroup01,

How are you coming up with X% of Yliters = $Z/ppm?

Is there some constant to describe how much ppmFC there is per %SodHyp?

0.9525
10.8% sodium hypo * 0.9525 = 10.3% available chlorine content.

[Sponge1971]

Here's a big azz wrench to throw in the works...

I just ran a 'Carl' on the jug of Walmart 4%.

1ml of Walmart 4% in my little 10liter 'pool' tests as 12.6ppmFC
(baseline tap water was 1.2ppmFC and sample read as 14ppmFC)

I'm fairly certain I didn't mess up. I will dump my 'pool' back into the 1liter measuring cup I used to fill it...in case I mis-counted. (even then...such a massive difference for +/- 1liter error?!?!?). I am 100% certain on the 1ml bleach sample. I ovefilled the syringe, bled the air, pushed out to exactly the 1ml line. I rinsed the syringe outside, then dumped it & flushed it. I stirred well, waited 10mins, re-stirred and multiple-flushed then pulled a 10ml sample.

If this method kinda points to %conc, then Walmart's supplier is pulling a fast one...to the consumer's benefit...which is w-a-y too suspicious. But...maybe it costs that particular supplier too much to dilute it down to 4%. -or- the supplier-du-jour only has 12% in their tanks...but, sometimes the other suppliers only have 4%...so Walmart has to mark for the least %conc. No doubt they have multiple sources for their store brand stuff. But I'd have to random sample all over the place to try and nail it down...forget it.

Anybody have anything to add?

UPDATE:
I just emptied 11 liters from the bucket. <sigh> That throws the math off...but that means the '%conc' must be even higher than 12%-ish. I just expanded the whole: 1ml in 11liters = 12.6ppm...up to my pool volume 20062liters for 1ppm change. I'm going to chuck 145ml of this stuff in and see what happens. My pool is 4ppm now. If it goes up to 5ppm, I guess it must be way more than 4%. True...I am only +/-0.5ppm resolution...but a little trinkle of 4% can't be worth much...the odds are it won't push me above 4ppm. We'll see....

[Sponge1971]

<sigh> a second update...
I wanted to work the angle on giroup01's suggestion of using CalHypo...
I have been searching around for info on whether CalHypo will increase my Calcium levels (which it will...so forget it)...and becuase I used "calcium hypochloride" in the search string...I ended up bouncing across a couple more "cost vs chlorine types" threads...and one driven by ChemGeek even. I'm sorry I missed them when I started this thread.
I don't want to flog a dead horse, and although I just skimmed the other posts (will get back to them...too late tonight) I suspect they are well and good for the cost vs chlorine I was trying to originally figure out.

Also...(not having read/searched other posts fully)...I also suspect Carl's post about determining PPM of the 'stuff' you have is the better place to continue the 'discussion' of the methodology and interpreting the results.

I don't know what other meat is left in this thread, after considering those other ones...I'm too tired now to suss it out.

Mod: if you feel this thread is now pointless and/or should be pmoved/closed/deleted...I trust your judgement. It's always best (and very hard) to keep like info (and usefull info) together...

[giroup01]

<sigh> a second update...
I wanted to work the angle on giroup01's suggestion of using CalHypo...
I have been searching around for info on whether CalHypo will increase my Calcium levels (which it will...so forget it)

Keep in mind that the pool will be opened about 4 months a year, and come October you'll drain it 2/3, whatever's left will be diluted by rain and melted snow, then you'll top it off in April with tap water.

So the increase in CH, whatever it is, is irrelevant.

[Sponge1971]

Well, not quite...

I have a DE filter so I don't dump & fill on a regular basis. Rainwater duming is all I'll be doing.

I plan to close my pool way late and open it way early. This is my first run but I'm thinking April to November...we'll see how reality goes...

I also only plan to drain below my returns, leaving them open to allow overflow to drain out the pool. Opening 'refill' will only be about 6 inches.

I have no idea on the 'rate of rise' my calcium would have, if I used CalHypo...but there won't be the dilution you're suggesting.