Request help to balance pool water

[witters]

I'm new to this site - I hope you can help - there always seems to be good, consistent advice on offer.
I have a vinyl in-ground pool, 32,000 litres. This is only my second year, so I still have a lot to learn.
I've only just opened it up this year. A little green on opening, but a good shock and a thorough clean and it's looking nice but very slightly cloudy. My issue is that my pH and TA are a little high so I haven't managed to fully balance. Saturation Index is 0.5.
I use Scuba II for testing. I am lead to believe that TA of 100 is ideal so I set about reducing it from 180. I know I have still got to get rid of 1.5 ppm combined chlorine but, rightly or wrongly, I believe the perceived wisdom is to adjust TA and pH first with acid and aeration before further shocking.

Before the initial shock after opening up, I got the pH down from 8.3 to 7.3 using 900 g of dry acid. After cleaning, my readings were pH 7.5, TA 180, CYA 48. I put in 1.2 litres 23% Hydrochloric Acid. A day later readings are pH 7.6, TA 180. Surely that ammount of acid should have reduced pH by 0.3 and reduced TA by 30? I find myself being confused.

Do I carry on adding acid and try the acid/aeration combo? How long should it take for the pH/TA to reduce? The pool shop did a test last summer and told me that the local water is very high in phosphates (off the scale they described it as!) Could phosphates have an effect on the acid? Since CYA is already at top end, I am now trying to use only liquid acid and liquid bleach.

I would be grateful for any advice. I do tend to worry about things - perhaps perfection is not an option!

Many thanks for your attention

[Denniswiseman]

Hi witters and welcome
First of all you really need to get yourself a decent FAS/DPD test kit (Taylor K2006c or TF Testkits TF100 if in the states) to get accurate results as maintaining an appropiate shock level means testing quite often during the day
If you are in the UK Teapot may be able to help source one
I had an Aquachek meter and it was well off
Use these common products to balance
Liquid chlorine (sodium hypochlorite or plain bleach)
Muriatic acid (hydrochloric acid) to lower pH and TA
Bicarbonate of soda to raise TA
Aeration will raise pH only
Soda ash will raise pH and TA
Don't panic about high TA if your pH is stable
Don't worry about phosphates the main issue is it's food for algae
Your Slam (Shock Level and Maintain) isn't finished if you have 1.5 CC and you are cloudy, continue the slam
Your Muriatic acid shouldn't have been that much to reduce the pH and TA I suspect faulty testing. I have checked with 14.5% and 29% and neither comes to 1.2Litres

[witters]

Thank you very much, Dennis, for your advice.
My water is now crystal clear. TA has gone down to 150 and pH seems to have stabilised at 7.8, so I may try reducing the pH a little (I suspect I may have over cooked the aeration). I'm in the process of killing off the chloramines so hopefully I will see the results of that in a day or so.

I take your point about the test kit. I bought the Lovibond Scuba based on good reviews and recommendations, but I agree, it does have its limitations. For what it is, it seems pretty accurate (on a test last year it calibrated perfectly with the expensive machine in the pool shop) but for peace of mind I will purchase a Taylor kit. Apart from any other issues, the Scuba is limited to maximum 6 ppm Chlorine and I can't test CH.

Both the K2006 and the K2006c are available here in France for 80 euros and 160 euros respectively. Apart from the size of the bottles, is there any advantage of the K2006c over the K2006? Given that the reagents only last a year or so, I'm not sure I would need the bigger bottles.

In respect of the acid dose, I based my calculation on the acid manufacturers instructions. 23% Hydrochloric Acid - 150ml per 10,000 litres per 0.1 change in pH. For 0.3 pH change, total acid therefore 1.4 litres. This compares with Pool Calculator (setting TA at 170) which gives a dose (extrapolated between 14.5% and 29% to get back to 23%) of approximately 0.97 litres. Why the difference, I don't know, unless it is simply that the manufacturers recommendation does not allow for variations in TA.


Thank you, again

[Denniswiseman]

The K2006C is considered better value 0.75oz against 2oz Depending on how often you test will determine the best value
When trying to reduce TA, use the amount of acid to reduce your pH first so that you don't go to low on the pH Then aerate to bring it back up if needed
The Pool Calculator works well and I use it all the time

[witters]

Thanks, Dennis
It appears that my information was not correct in respect of testers. Despite a couple of web-sites advertising them here, I have been told today by Lamotte that the liquid based FAS-DPD testers (both Taylor K2006 and Lamotte 7022 are illegal in the EU due to their non-compliance with European REACH regulations. I have posted on another thread relating to testers in the hope that maybe Teapot or others can suggest a European option.
Thanks for your help

[Denniswiseman]

Is that new legislation as I purchased mine from the States. Import duty and VAT was charged
Teapot spends a lot of time in France so may have additional info

[witters]

The original REACH regs go back to 2006 but I don't know whether there have been recent changes. All I know is what Lamotte told me. It seems that tablet testers are OK but liquid titration methods are not. They also told me that part of the non-compliance with the regulations was the lack of multi-language packaging. Teapot recommended Lamotte colorq pro 7 (also recommended by Lamotte, but then that is not surprising!) How long ago did you get your K2006c and are you able to get replacement liquids? Do they come from the States or is there a UK stockist. Ourpoolstore.co.uk say they stock them but they seem to be indicating supply problems. All very confusing.

[Teapot]

Sadly shops can get fined for not complying with reach regs. Obviously the odd shipment makes it through, also so does paying more money but that is my cynical side.
I am happy to post out but obviously there is an additional charge for postage.
I can also get FAS DPD kits from Palintest however they have a terrible customer service attitude and deal with the trade predominantly. Also their costs are generally much higher.

[Denniswiseman]

I bought mine from the states after 2006 and I also managed to get replacements through Ebay

[Teapot]

Probably because the US shipment wasn't from another EU country. They changed the formulation to make it shipable, the TFP couldn't be sent because Dave, the owner is an ********

[witters]

Thanks very much, guys, for all your help and advice. Because it's hot and my brain is fried, I've bitten the bullet and a Lamotte colorq pro 7 (tablet version) is on its way direct from UK, arriving in a couple of days (they still insist they are not allowed to sell the liquid version). I know some folks have misgivings about the CH test but Veolia are pretty transparent round here and they insist that calcium is consistent at 310ppm. Also, I believe you have to give the CYA test a bit more time and care.

Incidentally, my pool is now perfectish (at least according to baby Scuba - time will tell). Today I am reading FC 5.7 (still going down after shocking), CC 5.8, pH 7.6, TA 150, CYA 39, assumed CH 310. I am trying - honest! Shame I don't actually like swimming - this is all for the rest of the family.

[Denniswiseman]

Thanks very much, guys, for all your help and advice. Because it's hot and my brain is fried, I've bitten the bullet and a Lamotte colorq pro 7 (tablet version) is on its way direct from UK, arriving in a couple of days (they still insist they are not allowed to sell the liquid version). I know some folks have misgivings about the CH test but Veolia are pretty transparent round here and they insist that calcium is consistent at 310ppm. Also, I believe you have to give the CYA test a bit more time and care.

Incidentally, my pool is now perfectish (at least according to baby Scuba - time will tell). Today I am reading FC 5.7 (still going down after shocking), CC 5.8, pH 7.6, TA 150, CYA 39, assumed CH 310. I am trying - honest! Shame I don't actually like swimming - this is all for the rest of the family.

I take it that your CC of 5.8 you meant TC (total chlorine)

[Teapot]

(they still insist they are not allowed to sell the liquid version).

They are not, as an EU registered business they have to comply.
When your plastic test tubes go hazy in a year or two, order some new ones when you order your reagents.

[witters]

Quite right, Dennis. I mean TC. Still not fluent in lingua piscine. Thanks for the advice, Teapot. Will do. Onward and upward. Still got an extension to build before the planning permission runs out but I'm probably wasting my time and money with the current Brexit chaos. My wife says don't worry, therefore I don't!

[Teapot]

Aerating the water will raise your pH but leave your alk pretty much where it is and acid will bring down your pH and alk. Then you can reduce the alk over a period of time which makes the pH much more stable. You don't have to worry about CH or alk with a vinyl pool just as long as your pH is reasonably stable. The figure in charts and tables are for concrete/tiled/plaster pools. I run my pool with an alk of around 37-40ppm and do not add any ph- as the pH is very stable and I have water similar to yours, are you near Tours?