Not sure what my results mean - do I need to shock?

[maggie2712]

Hope someone can help me. I have just tested my water (using Taylor K206) results as follows:

FC 13ppm
CC 0.6
PH 7.2
CYA 110
CH 260 ( I know this is low)

Do I need to shock?

Thanks very much :-)

[Themadczar]

Your cya is very high... The test is inaccurate over 100ppm so yours could actually be higher. I would suggest retesting cya with half pool water and half tap water then double your result. Use the "best guess" chart here. Also, use the 10ml sample method when testing for fc and cc to save on reagents. If you have over .5 ppm cc, then you should shock.

[maggie2712]

Your cya is very high... The test is inaccurate over 100ppm so yours could actually be higher. I would suggest retesting cya with half pool water and half tap water then double your result. Use the "best guess" chart here. Also, use the 10ml sample method when testing for fc and cc to save on reagents. If you have over .5 ppm cc, then you should shock.

Thank you I will do that tomorrow as it is now dark. Am new to using the test kit so am a little wary as to whether I did the CYA test correctly. Thanks again for your response :-)

[Themadczar]

The cya test is tricky to read correctly. You want bright, indirect light. So ideally stand in sunlight with your back to the sun (your shadow directly in front of you) and view the dot in the comparator by holding it at your waist. You can also pour the sample back into the bottle and retest a second or third time to verify your results.

[Themadczar]

Forgot to ask... What are you using to chlorinate?

[maggie2712]

I have to admit I have been using pucks in the chlorinator as I wanted to use them up. I no longer have any left so it is back to bleach for me. I have followed the instructions given and retested the CYA this morning results as follows:

CYA 90

FC 15

CC - this is where I got stuck interpreting the reading. When added the 5 drops the water turned pale pink, added 2 drops of the other (sorry haven't got number of bottle handy) and the water turned clear again.

[Themadczar]

Ok, just so we are clear... 90 is the cya level after doubling the actual results? And for the cc, are you using a 10ml sample? If so, and it took 2 drops to clear the water then your cc is 1ppm and you need to shock (which is either 20 or 25ppm fc depending on whether your cya is 90 or 180.)

[maggie2712]

Yes, CYA is 90 after doubling. I don't know what the heck I did yesterday when testing CYA! Your instructions were spot on and helped me immensely.
I thought the CC was 1 but wasn't sure, and yes I was using a 10ml sample.
Thank you so very much for helping me I really appreciate it!

[Themadczar]

No problem. You also want to make sure you leave the pool uncovered as much as possible when the sun is on it... Sunlight and outgassing will help keep cc in check.

[Watermom]

Read the Best Guess Chlorine Chart in my signature below for more about the connection between CYA levels and needed chlorine levels.