Quote Originally Posted by meade
We have just purchased our first pool, just filled it, very new to all of this. It is a 24' AG. I just purchased a test kit (HTH 5 way). I have been reading this site non stop and have a question regarding CYA. Without this reading I cannot use the BleachCalc correctly......right? I did a quick test and the PH was good, Chlorine was very low. I could put in a 2ppm increase desired but if I understand what I am reading, I need the CYA level and Ben's chart before I can put in a correct figure? (ppm increase desired)

Also, I know reading so far I want my CYA levels around 30-40 ppm......once there it should never increase if I use ordinary bleach, correct?....and it will only decrease through water loss and adding new tap water?

Thanks........I feel like I am slowly learning......I hope!
Meade
Meade, welcome to the forum, you've done your homework. However, I think you are confusing the 'bleach-calc' by mwsmith with the 'best guess chart' by Ben, the bleach calc should give you the amount of bleach/ given strength to raise your water 'X'%, while the best guess tells you how much to raise it and keep it for a given level of cya. As long as you have a "0" reading of cya, the bleach you put in your pool will be burned off by the UV from the sun, and any 'stuff' in your pool. At 30-40 ppm, cya will help to keep some cl in the pool. Without it, you will not be able to hold a cl level in a sundrenched pool.
You are right that bleach will do nothing to your cya level and that you have to add it (cya), bought from a pool store . You've got the right idea.