Liquid vs powder/granulated - For town pool

Chlorinating, maintaining the right chlorine levels,
chlorine problems. Dichlor, trichlor, cal hypo, bleach,
granules, chlorine pucks and chlorine sticks.
mcsp
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My Pool: Community pool, 25mt, 5 lanes. 1mt deep to 1.7mt

Liquid vs powder/granulated - For town pool

Postby mcsp » Tue 19 Dec, 2017 17:12

Hello all, I've recently taken over the finances for the community pool and am looking at the most effective way to keep it clean. Currently, they go through 120lt / 32gal of granules a season (approx 4 months). The pool is around 50,6000 litres / 133700 gal, although I do not know the type of pump beside it being self-feeding (?) and levels are checked twice daily (council requirement). We have quite hard water so the liquid chlorine is appealing. Can anyone advise me on what to do? Thanks.


Teapot
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Re: Liquid vs powder/granulated - For town pool

Postby Teapot » Wed 20 Dec, 2017 03:22

MCSP. welcome,
You are going to have to get some more details in order that we can look at the situation carefully.
Results of a full water test, that is Cl free and total, pH, CYA stabiliser, Alkalinity, hardness.
Is the pool outdoor or indoor?
Average bather numbers?
What type of filtration?
Exact details on the granules (Calcium hypo, Dichlor, trichlor) or a combination with liquid chlorine (is that stabilised like Bayrol)?
And an idea of the pump specification?
Flow rate?
It sounded like you have an automatic dosing pump (self feeding)?
Also double checking 133700 US gallons = 506,054 litres?
Sorry it's all questions but sitting behind a PC we have to get all the information. On the face of it a communal pool using 120 litres of chlorine for a reasonable bather load pool of 506m3 isn't that bad.
Denniswiseman
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Re: Liquid vs powder/granulated - For town pool

Postby Denniswiseman » Wed 20 Dec, 2017 04:56

Hi MCSP

Apart from what Teapot has already said Liquid chlorine is the only sanitiser that doesn't add anything but salt (slowly) to the water
For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm

High CYA reduces the effectiveness of chlorine in your water and with your hard water you wouldn't want to increase your Calcium Hardness
The only way to reduce both would be by a partial drain and refill or Reverse Osmosis
Teapot
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Posts: 138
Joined: Tue 17 Oct, 2017 10:52
My Pool: 12 x 24 (45m3) liner pool, Triton TR60 filter with AFM glass media (Activate) and variable speed pump running 0.08HP
Location: UK

Re: Liquid vs powder/granulated - For town pool

Postby Teapot » Wed 20 Dec, 2017 06:22

Dennis you have to tread carefully, some companies like Bayrol make liquid chlorine that is stabilised with CYA. That's bound to be re badged somewhere. Probably not the only one either. lets wait for a reply.
Denniswiseman
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My Pool: 10k inground fibreglass, Telescopic Cover, Hayward Powerline pump, Quality filter with glass media, 27kw output heat pump, K-2006C test kit
Location: United Kingdom

Re: Liquid vs powder/granulated - For town pool

Postby Denniswiseman » Wed 20 Dec, 2017 13:25

Hi John
I was under the impression that CYA was used to bind the chlorine to a solid form
I don't understand why CYA would be added to Sodium Hypochlorite
Maybe we should say Sodium Hypochlorite or plain bleach instead of liquid chlorine
Teapot
Swimming Pool Pro
Swimming Pool Pro
Posts: 138
Joined: Tue 17 Oct, 2017 10:52
My Pool: 12 x 24 (45m3) liner pool, Triton TR60 filter with AFM glass media (Activate) and variable speed pump running 0.08HP
Location: UK

Re: Liquid vs powder/granulated - For town pool

Postby Teapot » Wed 20 Dec, 2017 15:55

Indeed Dennis, I have to admit it caught me out to when I was introduced to it. There is a liquid CYA available from HornerXpress which obviously doesn't take a week or two to dissolve.

You just never know what people and especially commercial are putting in the pools. I am playing it safe and asking these days (when I remember lol)
mcsp
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Posts: 2
Joined: Tue 19 Dec, 2017 16:44
My Pool: Community pool, 25mt, 5 lanes. 1mt deep to 1.7mt

Re: Liquid vs powder/granulated - For town pool

Postby mcsp » Sat 23 Dec, 2017 03:09

Thanks Teapot and Dennis, I'll pass this onto the pool maintenance person and see what we have.

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