Structured approach to salt water pool chemistry, help please.

Problems relating to pH and total alkalinity.
Increase ph, increase TA. Reduce pH, reduce TA.
pH chemistry advice and techniques for the pool.
Cameljockey
Pool Enthusiast
Pool Enthusiast
Posts: 23
Joined: Fri 13 Jan, 2017 23:48
My Pool: 55,000 litre, rectangular ceramic tile-lined, salt water, 10 years old.
10x4 metres, one 10m. side infinity edge opposite the four pool jets.
Emaux SSC25-T chlorinator
Emaux SPH150 1.5 HP pump
Emaux CF150 cartridge filter

No aeration other than very gentle trickle over the 10m long infinity edge.

Structured approach to salt water pool chemistry, help please.

Postby Cameljockey » Sat 14 Jan, 2017 00:02

HI all, I'm new to pool ownership but think I understand the basics, however re-starting a 55,000 litre pool is proving confusing. I would ask in what order I should do things (maybe starting with stabilisation first?).

I shocked the slightly green water (delivered by truck) which came out lovely and clear, added salt as recommended by my local pool guy, but the salt chlorinator was defunct and no longer serviceable so have replaced that and it's showing good salt level, with a slight salt taste to the pool water.

I have a pool kit showing ppm readings of:

Cl - 3 or greater (scale only goes to 3.0) - I re-shocked it 2 weeks ago as the Cl was gone and I had no chlorinator then, and I accidentally double-dosed.
I've turned the new chlorinator down to run at 60 pct to see how it goes, not exactly hot and sunny in Thailand these days, about 28 degrees.
pH - 8 or greater (scale only goes to 8.0)
Hardness - none
Total alkalinity - 110
Cyanuric acid - not registering (I added none so guess it's zero unless the shock had a small amount of stabiliser added)

I added 3 litres of muriatic acid over 3 days before the recent rains and it didn't lower the pH at all, unless it has but is still over 8? I have added no other chemicals.

As I said, the water (most of now, anyway, we had some heavy rains over 2 days) came by truck, but for interest my local water has pH 7.2 and TAlkalinity 470. So I guess it's very soft but still throws incredible sediments after just boiling a pan of water on the stove, which I don't understand. Soap also doesn't make bubbles, but makes a soapy film on your hands.

Can someone advise me in what order should I attack things to go about balancing my pool, so I don't have my chlorinator working overtime all year?

Thanks kindly!


Denniswiseman
Pool Industry Leader
Pool Industry Leader
Posts: 2594
Joined: Tue 06 Sep, 2011 05:48
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: Structured approach to salt water pool chemistry, help please.

Postby Denniswiseman » Sun 15 Jan, 2017 07:28

Testing your chlorine uo to 3ppm isn't really any good as you would need to base your chlorine on your Cyanuric acid level which should be about 70ppm with a target chlorine of 5ppm and a shock of 28ppm according to Chlorine / CYA Chart for SWG pools
SWG's tend to have higher pH but lowering your TA with muriatic acid will help to stabilise
Aerating will raise pH without raising TA this will happen if you have waterfalls,infinity edge and fountains
Check out the information here
balance your water for SWG's
Pool Levels
Pool Maths
Slam
Pool School

Bear in mind that
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
Cameljockey
Pool Enthusiast
Pool Enthusiast
Posts: 23
Joined: Fri 13 Jan, 2017 23:48
My Pool: 55,000 litre, rectangular ceramic tile-lined, salt water, 10 years old.
10x4 metres, one 10m. side infinity edge opposite the four pool jets.
Emaux SSC25-T chlorinator
Emaux SPH150 1.5 HP pump
Emaux CF150 cartridge filter

No aeration other than very gentle trickle over the 10m long infinity edge.

Re: Structured approach to salt water pool chemistry, help please.

Postby Cameljockey » Wed 18 Jan, 2017 14:16

Denniswiseman wrote:Testing your chlorine uo to 3ppm isn't really any good as you would need to base your chlorine on your Cyanuric acid level which should be about 70ppm with a target chlorine of 5ppm and a shock of 28ppm according to Chlorine / CYA Chart for SWG pools
SWG's tend to have higher pH but lowering your TA with muriatic acid will help to stabilise
Aerating will raise pH without raising TA this will happen if you have waterfalls,infinity edge and fountains
Check out the information here
balance your water for SWG's
Pool Levels
Pool Maths
Slam
Pool School

Bear in mind that
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


Thanks for the reply. I guess I need a better test kit for chlorine. Its an OTO test and the maximum reading is 3.0.
Denniswiseman
Pool Industry Leader
Pool Industry Leader
Posts: 2594
Joined: Tue 06 Sep, 2011 05:48
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: Structured approach to salt water pool chemistry, help please.

Postby Denniswiseman » Wed 18 Jan, 2017 16:38

I use the Taylor K2006C which I have to get from the states as it's not available here in the UK
Have you checked out those links as there is a lot of useful information there

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