After the rain my balance went bye-bye

iggy

Well-known member
Jan 24, 2008
175
The Cool Part of Arizona
Hi All,
I'm not going to get too excited yet but we had a rain storm that dropped about 2 inched on Monday. I had to lower the pool about the same 2". Last Saturday I added about 16 oz of liquid muratic acid 29% to try an lower my TA from 140 down to about 80 to prepare for the salt that will be added in about a week.

Last Saturdays readings
FC 5
TC 5
ph 7.6
TA 140
CA 250
CYA 100

Todays readings
FC 5
TC 5
ph 7.2
TA 80
CA 250
CYA 100

As per the pool calculators direction to lower TA you should use muratic acid and ph will also come down and you need aeration to bring the ph back up.


Is this correct?

Iggy
 

JasonLion

TFP Expert
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May 7, 2007
37,879
Silver Spring, MD
Yes, aeration will raise PH without increasing TA. You can use a fountain, spa jets, rain, kids splashing, an air compressor, etc. to provide the aeration.

I am concerned that there might be problems with the water testing numbers. It would take over a gallon of muriatic acid to lower the TA as much as you describe in 11,500 gallons. How are you getting the water test results? (Pool store or specific brand/model of test kit) Another thing to keep in mind: It is best not to allow the PH to go below 7.0. If the TA really went down that much the PH must have been far lower right after you added the acid (the rain would have increased it). Low PH can damage metal plumbing parts, especially copper heat exchanger coils in pool heaters.
 

iggy

Well-known member
Jan 24, 2008
175
The Cool Part of Arizona
Jason,
You are absolutly correct that 1 gal of muratic acid total over the past 6 days. Any I just double checked the numbers at the local Leslie's pool and they are good.
I tested the ph with my kit and ph was low but Leslie's Pools says it is 7.2
I have a aquachem pro kit which has been accurate as well as test strips.
I did get the Alk down to 80 which I wanted now we will run the waterfall and aerater to bring the ph up a little.

I can just imagion when we add the salt in a week or so what will happen to ph and alk.
I suspect both will rise.
Iggy
 

duraleigh

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Apr 1, 2007
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Sebring, Florida
Iggy,

I'm not an expert on salt pools, but I don't think the addition of salt alone will have much affect on your pool chemistry.

I'm also in agreement that your pH must've taken a pretty good dip adding that quantity of acid. Typically, it's a pretty good idea to drop it a little more slowly.
 

JasonLion

TFP Expert
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LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
No need to worry about the testing then. You mentioned 16 oz of acid and I knew that couldn't be right. Also, before you edited the post some of the other numbers were off, but now that you have corrected them and clarified the amount of acid it all makes sense.

If you added the acid in batches slowly over the week while tracking the PH then you are doing exactly the right thing.
 

iggy

Well-known member
Jan 24, 2008
175
The Cool Part of Arizona
JasonLion said:
No need to worry about the testing then. You mentioned 16 oz of acid and I knew that couldn't be right. Also, before you edited the post some of the other numbers were off, but now that you have corrected them and clarified the amount of acid it all makes sense.

If you added the acid in batches slowly over the week while tracking the PH then you are doing exactly the right thing.
Thank you for your helpful words.
Yes I did get back and edited the original post after I noticed a few errors.
I think I know what I'm doing but I still need reassurances from the experts.
I just consider myself very dangerious with the chemistry knowledge I have learned lately.
I think my wife is scared to go in the pool thinking her hair will turn blue or all fall out. LOL

Iggy
 
G

Guest

Your numbers look good. The salt will have no impact on your water balance until you turn on the SWG. Then things will change a bit but that is normal SWG operation.
 

cliff_s

Well-known member
Mar 28, 2007
93
The heavy rain we had a while back for some reason was very Acid and dropped everybody's pool
several points lower in pH.

I wouldn't panic as the pH will slowly come back up by itself. Mine is back to 7.6 now.

Our normal rain will slightly increase the pH.

I live in Sun City West, so I am very close.

Cliff s
 

iggy

Well-known member
Jan 24, 2008
175
The Cool Part of Arizona
Hi Neighbor

8) Hi cliff_s

We probably use the same Leslie's Pool place to check pur pool water (Reems/Grand)
Sometimes I like my reading better than theirs. I usually double check with my liquid kit as well as my test strips.
They just told me that my pH was 8 today and FC 1.5. I checked myself and it was pH 7.6 and FC 2.5
Oh well this is a continues learning process for me but I do feel confident in my readings.

Iggy from down the street in the Orchards Subdivision