Time to dabble with borates?

Kurtomac

Well-known member
Nov 18, 2019
66
Maryville, TN
For the most part I have ph rise in my SWG pool. 5 days ago I adjusted Ph from 7.8 to 7.4 and TA from 60 to 70. today it’s already back to 7.8 and 60. So added more baking soda and Muriatic acid. Is it time to dabble in borates?
Also concerning FC. At 40% on the salt system it’s been steady at 7-7.6. Should Lower the controller to 35% or is 7 ok for a 60 CYA. I just don’t wanna let it fall to low and be vulnerable to algae. Do you guys run tour FC right at the recommended target of 4 or a little higher to account from possible drops.
 

Msch99

Gold Supporter
Bronze Supporter
Jun 11, 2018
898
Verona, MO
I am not an expert, but I wouldn't add both baking soda and MA. From looking at many threads it seems each pool has it's own range of TA and PH where the PH rise is static to slowly rising.

I have seen some where this is PH at 7.8 or a bit higher, some like mine is a TA of 80 and PH has been hanging around 7.4 for weeks.
Another had a TA of 50ish and slow rising PH.

I would play with it, let PH get to 8, see how long it stays. Maybe drop it 7.8 again if doesn't work. Try different PH's by using MA only to see what happens.
As I said, mine likes 7.4, maybe unusual I don't know.
 

Msch99

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Bronze Supporter
Jun 11, 2018
898
Verona, MO
oh. forgot to mention. Any water features or bubbling in returns? Return breaking water surface? These all contribute to PH rise.
My Coleman has a air intake at the return to the pool. I tape it off so it can't pull air in and continuously increase the PH.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
19,254
Northern NJ
Why are you adding baking soda?

TA down to 50 is ok. Don't chase your TA. The lower your TA the slower your pH will rise. Raise your TA and it will cause you to yoyo your pH.

You will find pH of 7.8 and TA of 60 will be much more stable then what you are doing chasing TA of 70 and pH of 7.4.

Borates will not help the way you are managing pH and TA.

To illustrate the problem you are chasing you have to understand the chart below. pH and TA will constantly move to a point of equilibrium. The chart below shows how far off of equilibrium a pH/TA combination is. pH 7.8/TA60 is at 1.6 while pH 7.4/TA70 is at 7.7. Almost 5X more carbon dioxide trying to move the pH with 7.4 at TA 70.





 
Last edited:

kellyfair

Gold Supporter
Bronze Supporter
Jun 29, 2016
2,925
Tampa, FL
My pool hangs at about 7.5 ph for weeks if TA is 70 or so.

but that CYA could use a boost - it is low for a salt pool. See Chlorine/CYA chart in my signature.
 

Kurtomac

Well-known member
Nov 18, 2019
66
Maryville, TN
oh. forgot to mention. Any water features or bubbling in returns? Return breaking water surface? These all contribute to PH rise.
My Coleman has a air intake at the return to the pool. I tape it off so it can't pull air in and continuously increase the PH.
No water features. The only bubbles that get in the pool is from kids jumping and the tiny bubbles from the returns while the cell is generating chlorine.
 

Kurtomac

Well-known member
Nov 18, 2019
66
Maryville, TN
thanks for the info. This was my third time adjusting TA since March. I just figured middle of the range was best but I guess that destabilizes pH. I wish the sight glass on the PH meter had colors for 7.7 and 7.9 also. I thought it looked like 7.8 but coulda been a hair over and that’s why I made the ph adjustment. I thought I had read on here that anything over 7.8 could cause eye irritation and that lower pH allowed chlorine to work better. I had only dropped to 7.4 knowing it was gonna rise again so I wasn’t shooting for 7.4 as that to be my number to stay at...
It doesn’t sound like it’s reasonable to expect a stable pH under 7.8 without constant acid additions.

speaking of chlorine, what’s your thoughts on my initial question about it?
Why are you adding baking soda?

TA down to 50 is ok. Don't chase your TA. The lower your TA the slower your pH will rise. Raise your TA and it will cause you to yoyo your pH.

You will find pH of 7.8 and TA of 60 will be much more stable then what you are doing chasing TA of 70 and pH of 7.4.

Borates will not help the way you are managing pH and TA.

To illustrate the problem you are chasing you have to understand the chart below. pH and TA will constantly move to a point of equilibrium. The chart below shows how far off of equilibrium a pH/TA combination is. pH 7.8/TA60 is at 1.6 while pH 7.4/TA70 is at 7.7. Almost 5X more carbon dioxide trying to move the pH with 7.4 at TA 70.





 

Msch99

Gold Supporter
Bronze Supporter
Jun 11, 2018
898
Verona, MO
Target FC is 4ppm @ 60 CYA for SWG.
How far above that would depend on how long the pump / SWG run. If you run it 24/7 and maintain 4ppm you are good. If you run it 4 hours a day and lose 3ppm after shutting off, 7ppm a good target.

I usually try to run between minimum and target. Add doses of CL when grandkids are getting in.
 

Kurtomac

Well-known member
Nov 18, 2019
66
Maryville, TN
Here’s something else interesting that happened. I had checked my phosphates with my natural chemistry strips and it showed 300ppb and I had some leftover phosfree in the garage. I figured what the **** and put 16oz down each skimmer which is a hair less than the label called for for my pool size. Today I come home from work to test from my adjustments I made yesterday and on the floor of the pool in several areas was a lot of what appeared to be algae fallout and the water was a little more clear. I’ve measured some combined chlorine a few times here in the last couple weeks of testing but my free chlorine has been pretty consistent. I had 2 small spots of visible algae in the corners twice as well. Never did a slam as water seemed clear and was holding chlorine just fine. I wonder if the addition of phosfree sent any active suspended algae in the water to the chlorine electric chair since the algae had less food and was therefore more easily attacked by my FC?
Today’s numbers TA 70 pH 7.6 FC 7.0 CC 0