Can't decrease Alkalinity with Acid + Aeration

[cbird02]

I am setting up my vinyl pool and made a mistake when adding borax. I had purchased Arm and Hammer brand without knowing that it was Calcium Carbonate(Washing Soda) and not Borax. I used this last year and had two boxes left over. To make up the difference, I bought some 20 mule team Borax. I started with 1/2 my acid and 2 boxes of Borax...no problem! For the second half, I added my acid and then my Arm and Hammer...poof! Total milky cloud.(this happened last year with all A&H, but I thought it was just normal). Now I know to only use Borax.

So, on to my problem. I know the pool will clear up in a few days, but the Alkalinity from the A&H jumped to 150. I have attempted to reduce it by adding acid to bring to 7.0, then aerating. I have done 2 acid additions with 8 hour aeration sessions after that brought the PH up to 7.8 or so. The Alkalinity didn't budge! Its still 150. I have kept chlorine low so as not to mess with Alk measurements. First time chlorine was around 1 and this time around 2.

Vinyl Pool 4440 Gal
Sand Filter
FC 2.0
PH 7.8
Alk 150
CH 200
Borates 25
CYA 30

 

[Richard320]

Keep plugging along. It'll come down eventually.

As an aside, the TA test works even with high chlorine and the pH test is good up to at least 10 FC, so you can maintain normal chlorine levels without fear.

 

[Jimrahbe]

02,

Adjusting TA is a process and not a one time thing... You have to measure your TA and pH and then add acid to get your pH to drop to 7.0 and turn on the aeration. Wait about 3 or 4 hours and test again.. When the pH come up to 7.3 or 7.4 you do it again, over and over.. At first the TA will drop very little, but as time goes on it will drop more and more. It takes me two days to drop my TA.. I start early in the morning and do it all day until bed time.. I leave the aeration on 24/7... I will start testing again the next morning...

I usually drop my TA to 50 and find that it comes back to 60 pretty quickly, but takes months to get back to 120 where we just do all again.

Thanks,

Jim R.