High dry acid usage

pouyan_afshin

Member
May 11, 2020
16
San Diego
Hi Pool experts :):

I have a quartzite surface pool (25K gallon). I am keeping my Alkalinity between 60-80. The problem I have is that I feel like I am adding a lot of dry acid every month to the pool. I actually finish 50 lb of dry acid every month. I am not sure if this is too much, or this is the expectation for such large pool. I do not use chlorine tablets to prevent CYN to raise, but the problem with liquid Chlorine is that it is basic, so when I add it to the pool, PH will go up, and every other day I have to add acid again. Specially in this hot summer, I lose Chlorine much faster, so have to add Chlorine and acid next.

Two questions: (1) Should I keep the Alkalinity level 60-80, or 80-120 is the right number? I think I saw on your website that I should keep it 60-80. (2) Would you please recommend a solution to my high acid usage problem?

Thanks
Pouyan
 
Last edited:

markayash

Gold Supporter
Mar 21, 2016
2,438
Marietta Ga
I have a spa like yours and my PH goes up, I have a hard time keeping mine down.
I was using dry acid but read here it's not good to use over time so converted to liquid. Just bought 2 gallons of Pool acid for $12 at HomeDepot
 

setsailsoon

Gold Supporter
LifeTime Supporter
TFP Guide
Oct 25, 2015
3,338
Stuart/FL
Hi Pool experts :):

I have a quartzite surface pool (25K gallon). I am keeping my Alkalinity between 60-80. The problem I have is that I feel like I am adding a lot of dry acid every month to the pool. I actually finish 50 lb of dry acid every month. I am not sure if this is too much, or this is the expectation for such large pool. I do not use chlorine tablets to prevent CYN to raise, but the problem with liquid Chlorine is that it is basic, so when I add it to the pool, PH will go up, and every other day I have to add acid again. Specially in this hot summer, I lose Chlorine much faster, so have to add Chlorine and acid next.

Two questions: (1) Should I keep the Alkalinity level 60-80, or 80-120 is the right number? I think I saw on your website that I should keep it 60-80. (2) Would you please recommend a solution to my high acid usage problem?

Thanks
Pouyan
Pouyan,

Welcome to TFP! I'm trying to understand the problem instead of the question. I don't understand why you prefer to add dry acid instead of MA? As Marty said above liquid chlorine doesn't change the pH appreciably after it reacts. It's the aeration reactions that cause pH to climb. I limit the time it runs but my wife likes to hear and see it run. I think almost all of us have to add acid. I do the same thing as Mark. Lowering your TA will help. But I'd stay away from the dry acid.

Chris
 

pouyan_afshin

Member
May 11, 2020
16
San Diego
I have a spa like yours and my PH goes up, I have a hard time keeping mine down.
I was using dry acid but read here it's not good to use over time so converted to liquid. Just bought 2 gallons of Pool acid for $12 at HomeDepot
Thanks for the suggestion. I can also have the valve set in a way in which the majority of water returns to the pool and just a little bit returns to the Spa, so when it falls to the pool, it does not mix a lot of air in, due to low pressure. I am just worried that way I start developing Algae in the Spa.
 

jimbethesda

Gold Supporter
Jul 2, 2018
439
Austin, TX
Thanks for the suggestion. I can also have the valve set in a way in which the majority of water returns to the pool and just a little bit returns to the Spa, so when it falls to the pool, it does not mix a lot of air in, due to low pressure. I am just worried that way I start developing Algae in the Spa.
What equipment do you have? Any automation? Ideally, you should close that valve completely and program a spillover schedule from your automation for 30-60 mins a day.
 

pouyan_afshin

Member
May 11, 2020
16
San Diego
Pouyan,

Welcome to TFP! I'm trying to understand the problem instead of the question. I don't understand why you prefer to add dry acid instead of MA? As Marty said above liquid chlorine doesn't change the pH appreciably after it reacts. It's the aeration reactions that cause pH to climb. I limit the time it runs but my wife likes to hear and see it run. I think almost all of us have to add acid. I do the same thing as Mark. Lowering your TA will help. But I'd stay away from the dry acid.

Chris
Thanks Chris. I used dry acid because it is just easier to handle, that is the only reason.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,637
Laughlin, NV
Great -- put that in your signature.

Dry acid is Sodium Bisulfate. The Sulfate stays in the pool water. Once it builds to a certain concentration, it starts to destroy your Quartz finish. I would stop using it now. And drain off water at every convenience to lower the level in the pool water.