NUMBERS QUESTIONS for CHEM LEVELS of POOL

[michladny]

I finally bought my own testing kit (and will most likely order from here next season)...

I tested my water and got this:

pH - 7.4 (for three days already---it was supposedly 7.6 on Sun 6-4 when the pool store tested my water)
FC= 5
TC= 5
CC=0 (cause TC-FC=CC ???)
Alk - 100
CYA came back at 80 (I took my water to a "pool store" on Sun 6-4) and they said it was at 53 So could it have possibly gone up that much in three days? I let (am letting) the 2 pucks that were in the floater totally dissolve and now I am going to start to use bleach...... they wanted me to originally add 4 3" tabs to the floater PER WEEK---(YIKES!!!!! Glad I found this site!!!)
We have not been in the pool for days cause of the weather ----rain and then too cool)

Should I be worrying about my testing results for CYA and is my chlorine level too high?
Is there a thread with the numbers range for pool H2O on the site cause I did a search and couldn't find it?????

Thanks to you all, you have been such a big help!!!!!!

Michelle

[CarlD]

This forum and the Chlorine forums are the ones. Check the stickies. Also for chlorine vs CYA, check the Best Guess table--it varies.

Generally, your numbers are pretty good. But the CYA is a big question. Run the test again. Be sure the amount of pool water and reagent are EXACTLY equal (notice the lines on the bottle do that). Be sure to shake it for 30 seconds, hold the sight tube at your waist facing into the sun (do it on a sunny day) and move the tube around until you are certain you cannot even see a hint of the dot.

The NICE thing about the test is if you aren't sure, just dump the fluid back into the squeeze bottle from the dot tube and try again. I sometimes do this two or three times till I am sure. Why waste more reagent just because I filled the dot tube wrong?

IF your CYA is 80, then your FC is OK but at the bare minimum. If it's 50 (53 is meaningless) then you are absolutely fine.

Otherwise, your numbers are fine.

Do NOT use pucks--they will increase your CYA. Stick to bleach and you won't go wrong.

General desired numbers:
FC and TC--see the Best Guess Table
CC: 0, but anything less than .5 is pretty normal.
pH: 7.3 - 7.8
Total Alkalinity: 80-125ppm, but in vinyl without a heater, you can go up to 180ppm without worry.
CYA: 30-50, but see the Best Guess Table.
Ca or CH: Vinyl-- 0 - 500ppm, Concrete -- 200-400ppm

[michladny]

CarlD,

Can you explain why the Chlorine needs to be increased if the CYA is higher? Is it to make more Chlorine readily available to kill germs?
What if I take a little water out of the pool and refill? (just wondering)

Ok, I will tackle this later and run another CYA test when there is some sun out...

I am off to work:)

Thanks for your help:) MUCH APPRECIATED!!!

Michelle

[Watermom]

Read the thread at the following link. It might help you understand the correlation between cya levels and chlorine levels.

http://www.poolforum.com/pf2/showthread.php?t=2260

[michladny]

I think they way I am reading it is that CYA protects chlorine (what form?) and if it keeps it from being "diluted" from the sun (and others stuff) then why do you need more for a higher CYA level....CYA is what is protecting it...right?????

[Rangeball]

Yes, CYA bonds with chlorine (any kind, chlorine is chlorine) to prevent it from being lost from UV rays, but also weakens it's sanitizing ability somewhat. That's why you need a higher FC reading the more stabilizer you have, to get you to the same sanitizing power as FC with no CYA.