pH & TA lowering, help please

Jump to latest Follow Reply
H

Hawknz

0
Nov 30, 2015
44
Mardella, Western Australia
Hi All,

I'm trying to lower my TA (180), I am following the guide on here on how to do so. I am also using poolmath

Yesterday my pH (7.8) using the calculator I initially tried to lower it to 7.5 just to take it easy as this is the first time I have done this process. I calculated using the poolmath that I needed to add ~700ml of acid, which I did.

I retook the pH again an hour later with pump going, it appeared to not change at all (7.8), so I added a further 600ml of acid. Decided to leave it overnight. I also did an acid demand test which basically indicated I needed to add the same amount again.

This morning I checked pH (7.6) so it appears that despite the amount of acid I am putting in its not doing a lot.

I also notice when I entered the TA in pool math it readjusted the amount of acid I need (significantly increased it), I can understand this but I want to check if this sounds right before I go plunging more acid into the pool?.


Also on a side note can someone explain why aeration raises pH? just curious for my information

thanks
 
Follow the article precisely.... get your pH down to 7.0 - 7.2 regardless of how much acid it takes.

The acid/aeration process to lower TA:
  1. Add acid to lower your PH to between 7.0 and 7.2 (this also lowers TA)
  2. Aerate until PH rises to around 7.6 (the only way to raise PH without also raising TA)
  3. Repeat steps 1 and 2 until you reach the desired TA.
Click to expand...




 
Aeration increases the rate of CO2 outgassing from the water.

From what you are describing you are not really aerating in the sense that the aeration needs to break the surface of the water. Just running your pump will be slow.

The easiest way to provide aeration is the invert the return jets upwards so that the water is being returned via the breaking of the surface of the water.
 
Hi Jezza,

As duraleigh pointed out, I'm firstly trying to get my pH down so I can start the aeration, I'm waiting for it to get to 7.0-7.2 range, then I can use the spa jets at the side of the pool to provide aeration. I didn't want to aerate before getting the pH down until i know my pH is down for sure.

Its taken a heck of a lot of acid (2.7L) so far, ...as of now I'm sitting around 7.2-7.4 so it looks like i'm getting there, I was just cautious having not done this before
 
You can keep actively trying to lower TA by lowering pH to 7.0 and adding a source of aeration to help drive the pH up faster, then repeat until you get to the desired TA. However, if you simply maintain pH by just adding acid once your pH rises to above 7.8 it will happen over time and eventually your pH rise will slow to a crawl and your TA will be at the proper level for your pool. You're not that far off from a plausible TA to maintain so I would go that route.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply