PH and Alkalinity

[Mep32jep]

Latest readings on pool showed

FC-3
CC-.5
PH-7.8
TA- 50
CYA-30

I have had little bit of algae show up and wanted to knock it out. I know CYA is low and I have more to put in. I will also bring pool up to Slam to get rid of this algae.

My question is this. According to the SWG balance I need to get my pH to around 7.6 (which calls for 9oz of acid) and my TA to around 70 (which calls for 127 oz baking soda). In reading I know that lowering pH with acid will also reduce my TA. Does the pool calculator already take that in consideration with the recommendation of 9 oz of acid or do I need to plan on adding more baking soda? Should I even adjust pH. Is there away to lower pH and not affect TA? Thanks for your help.

 

[karmabiker]

Don't sweat the TA. Bring the pH down to 7.2 and follow the slam procedure. Remember that the M in slam is maintain, check your CL level early and often.

Once you finish the slam you can adjust the TA ... if you deem it necessary. It is generally one of the last things to bring in line and the appropriate level for your pool will be be up to you to determine.

 

[Mep32jep]

Thank for the reply. One question, in reading water balance for SWG it says to never lower pH below 7.5. Any particular reason to drop to 7.2?

 

[Richard320]

Thank for the reply. One question, in reading water balance for SWG it says to never lower pH below 7.5. Any particular reason to drop to 7.2?

Yes.
1) During the SLAM, yours is a bleach pool. Balance for SWG doesn't apply.
2) You can't measure pH accurately during the SLAM, and pH rises as a general rule. So you adjust it before the SLAM and hope it stays in range for the duration.

 

[Mep32jep]

Makes sense. Thank for the help