relatively new pool - ph high

JamesRansome

Member
Dec 23, 2020
7
Perth (Aus)
Hi all, been reading a lot here lately, our pool has been in for about two months and in use for a few weeks since they finished paving. For the past two weeks I have had a consistent ph reading of 8.2 on my chlorinator. (astral eq25)
These are my test results from the pool shop (I'm waiting for the recommended testing kit to arrive):
CYA 40
TC 4
FC 4
PH 8.2
TA 102
Calcium 160
water is clear and have had no issues swimming

Weather here is about 104F every day this week and the pool gets sun all day. Last night I decided to try add 900ml of muriatic acid to try lower ph, I used the chlorinator function for this. I let it do its thing while I went to bed and let the pump run through the night.
To my surprise ph had actually increased to 8.4 this morning..Am I missing something? Is it simply due to evaporation? I have been letting the pool breathe in the hot weather as recommended by the pool company.

Pool shop told me to add 2.5kg of baking soda and 2.5kg of calcium when I got the test done, I have not done this at the moment as I would like your advice first.

Many thanks,
 

aussieta

Gold Supporter
TFP Guide
welcome to tfp
do not add the baking soda, you dont need it and it will make your ph rise faster
you really need a quality test kit of your own. tf100 or taylor2006c or clear choice labs
add more acid with pump running, retest in 1 hour
repeat as required until you get a reading in the 7's
unsure on the calcium as their have been a few strange fibreglass pool issues lately
 
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JamesRansome

Member
Dec 23, 2020
7
Perth (Aus)
yes, I did forget to mention we have a clip on spa that overflows into the pool when the pump is running. I've ordered the CCL test kit, but ph is monitored on the eq25 and it is actually supposed to keep it to 7.4 by automatically dosing acid.
 

JamesRansome

Member
Dec 23, 2020
7
Perth (Aus)
It was installed by the pool company but it looks correct to me. I can actually see the acid move through the tube when I dose, so I'm not sure if something else is wrong with the equipment. I added 600ml this morning and 600 this evening and ph has stayed at 8.3. I double checked with the cheap kit they gave me and had the same result. Do you reckon it should have moved if it dosed properly? I guess the only way to find out would be to manually dose and check again..
Still swimming without any irritation by the way.
 

aussieta

Gold Supporter
TFP Guide
i would get a cheap ph test strip to double check
most ph tests max out around 8.2, so 9.5 would show as 8.2
maybe you are so far over that it will take time to get believable readings
are you using 36% hydrochloric acid or half strength
i would be getting concerned about now, get a reliable ph test, maybe try a few different pool stores until your test kit comes in
a high ta and spillover spa can cause rapid raises in ph, try to reduce spa run time if you can
 

JamesRansome

Member
Dec 23, 2020
7
Perth (Aus)
using half strength. The EQ25 displays higher numbers so I don't think it's off the charts, it has been in the 8.2 - 8.4 range for the past days. I will try bypass the spa completely today.
 

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JamesRansome

Member
Dec 23, 2020
7
Perth (Aus)
finally added 500ml 29% MA (+500ml water), the astral reading went down to 7.7 within like 5 minutes. Crazy. I hope it stays in range now, handling acid terrifies me tbh!
 

Brad_C

Well-known member
Nov 15, 2018
153
Perth, Western Australia
handling acid terrifies me tbh!

Hydrochloric acid isn't exactly spawn of the devil. If you spill it on your skin it'll sting/burn a bit and wash off easily unless you have broken skin, where it will sting/burn a *lot* and then wash of easily. It's significantly less vicious than sulphuric (particularly on clothing). I did something particularly dumb and splashed a drop of > 30% hydrochloric in an eye so i jumped in the adjacent 19kL eye wash bath and swam around with my eyes open. The sting went away and no further issues.

Just treat it with a bit of respect and don't do what I did.
 

JamesRansome

Member
Dec 23, 2020
7
Perth (Aus)
well, 2 days after my previous dosing ph was back at 8.3. I haven't touched the pool for a few days because of the crazy easterlies we get here around the hills. After reading a bit more on the forum, I decided to just add the acid this time without water, probably about 600ml, ph came down to 7.4 within minutes. Wonder what it will be like in 24h.

I received my test kit today but only had time to test FC and CYA so far. FC came back at 7, CYA at about 40, similar to previous pool shop reading. FC might be at 7 because the pool has been covered the past 4 days. Putting the cover back on before bed so half the hills doesn't end up in my pool again tonight. Another crazy hot week ahead, Brad!
 

setsailsoon

Gold Supporter
LifeTime Supporter
TFP Guide
Oct 25, 2015
3,865
Stuart/FL
Pool Size
12800
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-30 Plus
What is your TA? Your test kit results are more accurate than most pool stores. Please post a complete set of results from your test kit.

Thanks.

Chris
 

Brad_C

Well-known member
Nov 15, 2018
153
Perth, Western Australia
If you have your test results, the poolmath calculator will have a pretty good stab at calculating what you need to sort your pH. Given what is happening I'd be interested in seeing the total alk test results.

When I moved back into our house after 6 years of tenants it was sky high. Our tap water in Dianella has TA >150ppm and the tenants had been following the advice of a pool store who had a duff test kit and just adding kilos of bicarb. The pH was always rapidly drifting high. A few years ago I made a concerted effort to get it below 100 and it's been good since. When it creeps up to 150 I knock it back down to ~60 and away it goes again.

Those Easterlies have been a killer. Yay heat! More time in the pool.
 
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JamesRansome

Member
Dec 23, 2020
7
Perth (Aus)
My TA was 100 (4 drops until it turned pink, CCL test kit, the test for +100). Same as pool shop test two weeks ago basically. I have been topping up the pool once a week, I will test the tap water in the coming days. Ph still at 7.5 this evening (pump ran 8 hours today). I followed poolmath for the acid amount, works quite well, maybe keeping the blanket on will stop it drifting so fast? (the pool gets sun all day)

I will also ask the pool company why their equipment isn't doing this for me like it is supposed to.
 
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