CH Levels

[mindshank]

Tested today and yesterday using my new TF-100 kit love it! Got high CH numbers both days but think I misread yesterday versus today's. Anyway here's my #'s for 6/13:
FC-3.5
CC-0
TC-3.5
PH-7.5
TA-180
CH-700 I'm pretty sure i misread this one.
CYA-20
Temp-75

And my #'s for today 6/14:
FC-4.5
CC-0.5
TC-5
PH-7.5
TA-150
CH-450
CYA-29
Temp-72

I did the first test outside in the sun and found it difficult to read. I took my second sample in the house where it was much easier to read. As I have a vinyl liner should I be worrying about my CH levels? I am also using tri-chlor as my primary sanitizer and bleach to shock when needed so i don't really want to add any CYA as i'm almost in the ballpark anyways. As for the rise in FC i use a chlorinator and opened it up a bit more to get closer to the 5 ppm range. The pool is crystal clear. Thanks for your help!!

 

[JasonLion]

Hopefully CH really is 450 and not 700. High CH levels are a risk for any kind of pool. You want to be careful that you don't let PH get too high or you might get some calcium scaling. Since you are using trichlor, that shouldn't be too difficult to arrange.

 

[mindshank]

Hopefully CH really is 450 and not 700. High CH levels are a risk for any kind of pool. You want to be careful that you don't let PH get too high or you might get some calcium scaling. Since you are using trichlor, that shouldn't be too difficult to arrange.

So basically i'll check CH again tomorrow and if it is closer to 400-450, which i'm assuming it will, dont worry about it?

 

[mindshank]

Here's my numbers for today:

FC-6
CC-0.5
TC-6.5
PH-7.5
TA-140
CH-330
CYA-35

I'm getting comfortable with the CH test it doesn't turn a bright blue more of a light purple blue. So i guess my question is a CH of 330 anything to worry about i'm thinking no sine it's only 30 ppm over the recommendations on the pool calc. Once again thanks for help!

 

[JasonLion]

CH at 330 is just fine. Even CH at 450 just means you need to keep PH at 7.8 or lower.

You need to watch out though because purple can mean a fading end point, which can invalidate the test results. The sample may turn purple during the test, or go to blue for a moment and then turn back to red/pink. This is called a "fading endpoint" and is caused by interference from metal ions. If this happens, do the test again, but this time add five drops of R-0012 before adding any R-0010 or R-0011L. Remember to count the initial five drops in the total. In extreme cases, a fading endpoint may occur even when adding five drops of R-0012 at the start. If that happens, mix pool water with an equal quantity of distilled water, test that, and then multiply the result by two.