Re: cya & chlorine levels
With 17K gallons, your PF is 7. Calculate doses like this:
active% x pounds chemical x PF = ppm change
eg: 1.00 (cyanuric acid) x 1 pound x 7 = 7 ppm (per pound of CYA added)
eg. 0.55 (% chlorine in dichlor) x 1 pound x 7 = 3.85 ppm (chlorine per pound of dichlor added)
eg. 0.50 (% stabilizer in dichlor) x 1 pound x 7 = 3.5 ppm (stabilizer per pound of dichlor added)
8% plain household bleach has about 0.7 lbs of chlorine gas equivalent, so:
eg. 1.00 (% chlorine in chlorine gas) x 0.7 lbs Cl2 (per gal 8% bleach) x 7 = ~4.9 ppm (chlorine per gallon of 8% bleach added)
Re: cya & chlorine levels
I love math and knowing how to calculate everything, but I find it much easier to go to poolcalculator.com and use the tools there... Especially the last one on the page which tells you the effect of adding X amount of chemical Y to your pool (just make sure to input your pool size in gallons at the top).
Re: cya & chlorine levels
Another calculator that many of us like better can be found at the following link. I know that a lot of people do use the calculator that Themadczar mentioned above but it sometimes encourages people to put in a lot of a chemical to try and get to the target in one large dose rather than sneaking up on the target like we prefer.
http://www.poolforum.com/pf2/showthr...18-bleach-calc