Quote Originally Posted by rkrgk View Post
Before a month or so, I had good CYA levels (60-80ppm if I remember correctly). I was using trichlor tabs as well. I would think it added some CYA on top of what I already had. Not sure where all the CYA disappeared suddenly. Even though I backwashed few times during this process hard to believe it disappeared that way.
It doesn't take very long for an algae outbreak to break down your CYA, and if you've been fighting it for this long, that's probably where your CYA went. If that's the case, one of the frequent byproducts of that process is ammonia, which creates a HUGE chlorine demand in the pool until it's broken down by the chlorine. Measuring your Cl at night and again in the morning will tell you a lot more about what's going on in your pool, because if you're still losing chlorine overnight, it's due to the water, not the sun.

High CH can cause cloudiness in the pool, especially with high pH and high TA, although my money is on dead algae that hasn't been filtered out....