Measuring parts per million

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yogibear
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My Pool: 130,000 jr. olympic. metal walls, concrete bottom. shallow 3 ft, deep end 9 ft.
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Measuring parts per million

Postby yogibear » Thu 31 May, 2012 19:04

Hi guys, trying to determine what 2-3 parts per million (suggested in pool school) would be for a 130k gallon pool. Currently I put 5-6 scoops of granular chlorine daily but looking to switch to bleach to keep cya low. Currently at 40 ppm. Your help on this is appreciated. My current chlorine FC is at 8 ppm no chloromites.

Thanks!


pirateslovebacon
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My Pool: 18K gal, SWG, PebbleTec, solar & gas heat, Intelliflo VSD, Pentair cartridge, Jandy AquaLinks control system. Pool Pal for Android.
Location: SoCal

Measuring parts per million

Postby pirateslovebacon » Thu 31 May, 2012 19:33

You should be able to plug your numbers into the pool calculator to get that.
yogibear
Pool Newbie
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Posts: 2
Joined: Fri 18 May, 2012 11:42
My Pool: 130,000 jr. olympic. metal walls, concrete bottom. shallow 3 ft, deep end 9 ft.
Location: United States

Measuring parts per million

Postby yogibear » Thu 31 May, 2012 20:53

Thanks, I did. I was hoping it was wrong. It was saying 2 PPM was close to 400 oz of bleach. Putting that into numbers that is $10/day in FC. Just wanted to be sure :)
pirateslovebacon
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Posts: 12
Joined: Mon 23 Apr, 2012 09:45
My Pool: 18K gal, SWG, PebbleTec, solar & gas heat, Intelliflo VSD, Pentair cartridge, Jandy AquaLinks control system. Pool Pal for Android.
Location: SoCal

Measuring parts per million

Postby pirateslovebacon » Thu 31 May, 2012 21:37

Well, make sure you put the correct percentage strength in the calculator. Also, I'll mention CYA just in case you hadn't considered it (although I'm not sure you can use it in a commercial pool if that's what you've got).

However, 130K gallons!? Ain't nothin gonna be cheap about that. Many, many years ago, when I was a pool operator, our pools had oil barrel sized drums of bleach/chlorine. I can't remember how we got them, but you might want to ask a public pool such as an apartment community or HOA for some commercial supply references. A quote or two wouldn't hurt.

Also, at trouble free pool I recently saw a thread that was breaking down the cost of bleach from various stores across the US. They were breaking it down per %, and there was a spread sheet of results (Google docs if I remember correctly). I don't use bleach anymore, but I thought I was getting a good deal from Home Depot when I did. The stuff they're finding is half the cost.
chem geek
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Measuring parts per million

Postby chem geek » Fri 01 Jun, 2012 01:30

I get 12.5% chlorinating liquid from my local pool store for around $3.50 per gallon, but for 130,000 gallons of pool water then 2 ppm FC would be 2 gallons of 12.5% chlorinating liquid or $7 per day. You could find an off-brand Ultra bleach for less, but still probably around $5 per day. Nevertheless, it shouldn't be more than what you are using with chlorinating granules unless you are using Cal-Hypo which is sometimes cheaper. The problem is that it increases the Calcium Hardness (CH) level over time. That's OK if your CH is low and you've got a vinyl pool so don't need higher CH initially, for example.

If you are using Trichlor pucks/tabs or Dichlor chlorinating granules, then they will be more expensive if you also account for the pH/TA adjusting chemicals you also need. A 130,000 gallon pool is going to be expensive to maintain no matter how you look at it. You can cut down chlorine usage by having a higher CYA level (with a proportionally higher FC -- the higher CYA shields more chlorine at lower depths in a non-linear way). You could use a mostly opaque pool cover. I have a mostly opaque pool cover and spend $15 per month on chlorine even though the pool is used every day, but I only use 1 ppm FC per day due to the cover and my pool is "only" 16,000 gallons.

You say your FC is at 8 ppm, but what is your CYA level? It sounds like maybe your FC target might be too high, unless your CYA is close to 80 ppm.

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