About two weeks ago I added three pounds of CYA to my pool...It is between 13900 and 14000 gallons. I was getting away with adding only about 64 ounces of bleach per day (5.5 percent) After heavy rain or heavy swimming...son had a pool party last week ten boys...I would add more like 120 ounces...just to bounce it up...However this past weekend I tested my CYA and it was non existent...Had my friend test with her TF kit, and it was between 10 and 20 she said. So this is my problem...I was going through some notes today that I had taken from the forum and forgotten. And my notes said that CYA for pools that get large amounts of sun should be balances between 80 and 100 ppm. My pool gets total sun from about 10 am to 6 pm. Should I be adding more CYA to get it up to 80 parts per million. If so what is the best way to introduce...Through the skimmer is what the instructions say. The other thing is how long to let the pump run after I do so...and could my Nature 2 have anything to do with this...I have had in on the pool for about a month...and so many people told me to take it off that I have taken it off tonight so return water goes straight to pool now not through the secondary N2 filter. Could all the metals and minerals that thing puts in cause problems with CYA??? Should I shoot the CYA up to 60 to 80 or better with all the sun light I get?