TA test with high FC

[djdonte]

The TFT directions say, "NOTE: In the presence of high chlorine, initial color after addition of R-0007 may be blue and shift to yellow at endpoint. However, the test is still valid if so."

I'm using a magnetic stirrer. My test turns blue at 5 drops and yellow at 6. I have 19FC right now so makes sense. Is the test over at blue or yellow? Do I have 50 or 60 TA?

 

[mknauss]

60. But it does not matter much. Both are fine.

 

[djdonte]

Thanks. I've been trying to get the TA down but its good now. The pool wants to sit at 8.2pH. I usually add a bit of MA twice a week to get it back down to 7.8 but it seems my CSI now goes to -0.41 if I do this. Its at -0.03 now. Should I leave it or adjust pH down?

 

[mknauss]

If your TA is really 50, then you are likely reading your pH too high. An 8.2 pH would be a very purple color. Is that what you are seeing.

 

[djdonte]

It's a pinkish color darker than the 7.8 comparator. Its closer to the 8.2 color. None of them look purple.

 

[mknauss]

Above 7.8 has a purple hue. If it is still pinkish, then it is in the 7's.

 

[djdonte]

I don't see any purple tbh. The 7s look closer to salmon and the 8.2 is darker pink.

 

[mknauss]

The background effects the color you are seeing. Always use a bright white background.

Also the intensity of the color is not significant. Only the hue.

 

[djdonte]

I usually do it outside but its cloudy and rainy here. I just wanted to show you what I was working with to make sure I'm not missing anything. It looks like 8.2 to me.

 

[mknauss]

Looks mid to upper 7's to me.

Remember -- IF you have a TA of 50 ppm, it is chemically very difficult to have a pH of 8.2.

 

[djdonte]

My TA is 60, but I dont understand the chemistry behind your statement.

 

[mknauss]

PH TA Relationship - Further Reading

www.troublefreepool.com

 

[djdonte]

Great. Thanks for your help. Shouldn't I do something to get the CSI higher than -0.41?

 

[mknauss]

In winter that is not much of an emergency. Quit adding acid so much and the TA should stabilize or increase a touch.

 

[djdonte]

Sounds good. I will do that. Thanks for the help and insight!