Pool Calculator question

dykes26

Well-known member
Aug 17, 2009
184
My TA has recently dropped to the suggested level in the pool calculator based on the TRF method and the use of a SWG. Now that all my numbers are within range the calculator is reading the potential for plaster corrosion. What am I not getting?

Test results as of today-

FC- 4.0
CC- 0
PH- 7.5
TA- 75
CH- 275
CYA- 80
Salt- 3400
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
When one lowers the TA to reduce the rate of pH rise in an SWG pool, one either needs to keep the pH higher at 7.7 to 7.8 or needs to have the Calcium Hardness (CH) higher or some combination of both to keep the pool closer in balance. The salt in an SWG pool makes it more corrosive lowering the saturation index by about 0.2 so that needs to be compensated (along with the higher CYA and lower TA). You can raise the CH to 400 ppm and should be fine, especially if the pH is around 7.6 to 7.7.

By the way, what is the "TRF method"?
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
23,062
SouthWest Alabama
You're only at -0.4 CSI so that's not in the serious range. Following Richards advice will get you better numbers but I wouldn't worry about a -0.4. I wouldn't worry about doing anything until it gets closer to a -0.6.

How are you testing?
 

dykes26

Well-known member
Aug 17, 2009
184
Taylor 2006 test kit is the one I'm using. My TA has slowly dropped as I have added acid to balance the PH. So at this point a higher level of CH and a higher PH is what I need.

Somebody posted that as the PH gets into the higher range that is what causes the red eye effect. Is that correct?
 

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