The equation for liquid chlorine is: $cost/gallon x 1gallon/9.7pounds x 1/10.8% by wt available chlorine One caution though is that it takes *technique* to distribute the CYA powder, because it won't work in a sock like the granules do, but, once you know the technique, it's even easier than using CYA granules, and certainly far cheaper than the so-called "liquid CYA" you can buy in the pool stores.Īssuming the HASA liquid chlorine averaged $3.59/gallon after all the value-pack coupon and buy-11-get-one-free complicating shenanigans: So, in a single sitting (about an hour), I can bring up a pool from zero PPM to 50ppm CYA, so that the liquid chlorine has a chance of lasting in this perennial sunlight.Īs you noted, all the solid pucks and most of the "shock" powders also contain CYA, and I also use them (when appropriate, e.g., when I go on vacation), so, there is nothing wrong with the "slow" method either. The powder is available from *any* pool store that buys liquid chlorine from HASA (which is common out here in California), and they sell it in any desired amount at the *same price* as they sell the CYA granules. I used to add about 15 pounds of the *granules* to bring up the CYA fromĠppm to about 50ppm (we have a *lot* of sun out here), but this year I added 15 pounds of the CYA *powder* which is *very easy* to do once you know how! You bring up a very good point about the stabilizer!Įvery year I empty my pool (a bit under 40K gallons) and fill it back up again, so, I have to add the cyanuric acid (CYA) stabilizer. (assume 36% if it's not listed, which is what I've found out by calling *every* manufacturer who didn't list the percentage! They're trying to hide a lousy number every time!). Given the percentage confusion above, we can then add solid equations, to finally get these generic equations for calculating the true cost of sanitizing chlorine for all three types:Ī) liquid chlorine: $cost/gallon x 1gallon/9.7pounds x 1/10.8% by wt available chlorineī) liquid bleach: $cost/gallon x 1gallon/9.0pounds x 1/5.7% by wt available chlorineĬ) solids: $cost/pound x 1/?% by wt available chlorine, as listed on the container In both cases the actual strength varies with age where the turnover in the HASA chlorine is extremely fast (they go through a few pallets a day!) while the turnover in bleach is dismal by way of comparison (however, the *lower* the percentage of chlorine, the longer it lasts (which seems counter intuitive, to me, but I have confirmed this will phone calls to Clorox folks). However, the HASA liquid chlorine is listed by trade percentage, so 12.5% trade chlorine is 11.6% available chlorine. % of product (weight % of product) is extremely confusing to me but, it makes a huge difference in the calculations of cost for chlorine! Specifically, bleach percentages are listed by weight, such that 6% bleach is 6% by weight, or 5.7% available chlorine. Trade % (volume % Available Chlorine) vs. This lousy issue of % Available Chlorine vs. I should have provided more details about the percentage. If you average the first-trip cost of $3.85/gallon & the second-trip cost of $3.32/gallon, which is about $3.59/gallon, overall. It's still $18.40/case + 8.75% tax for one case, but if you buy two cases, the price has changed to "buy 6 gallons get 2 free", whose math turns out to then be 6 gallons x $4.60 each gallon + $0.41 tax each gallon = $30.00, plus tax on the two free gallons at $0.41 each, which turns out to = $30.82 for 8 gallons, or ~$3.85/gallon of 12% HASA liquid chlorine.īut, you always get a card for "buy 11, get 1 free" at the store, so, you end up subtracting $4.60 from that on every second visit, so, on that second visit, you end up subtracting $4.60 but adding $0.41 tax, which nets in a second trip cost of $30.82 - $4.60 + $0.41 = $26.63, which then comes to $3.32/gallon on that second trip. HISTORY: It used to be "buy one case, get one case free", which was pretty simple because one case of 4 gallons was $18.40 + 8.75% sales tax added $1.61 which made each gallon $4.60 + ~$ 0.41 tax ~= $5.00/gallon out the door if you only bought one case, but, with the free case, that added just the ~$1.61 tax (California makes you pay tax on free stuff), so for 8 gallons, it used to be simple at $18.40 + 2($1.61) = $21.62/8 = $2.70/gallon.ĬURRENT: Now, it's no longer that simple. SMS turned me on to the "Pool Store" in Saratoga, which runs a "special" all the time on HASA 12% liquid chlorine (I buy 16 gallons at a time), which has the following math, if interested.
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