So I've already added enough CYA to up the amount to 10 (according to bottle directions) but it's still at 0. This is powder form. Regardless, all of my other readings have been in the right range for over 2 weeks straight (including CC below 0.5 and FC around 2-3) by adding about a gallon of bleach a day. WEather is still cool here in central IL. My question is this: if my pool is doing just fine without CYA at this point, why should I add any???