So this seems to be a common first post, but I'll do it anyway.
Just bought a new house with my first pool. Yea!! 25,000 gallon, IG, concrete (gunnite and plaster, I believe) with DE Filter in Tucson, AZ. When we got it, there's a floating chlorinator with a handful of 3" pucks in it. Water looks nice enough... I finally got around to having the water tested and they claim the CYA is "over 165" and tell me to drain 60%, refill and retest. Hmmm something fishy here.... Time to get smarter - To the internet!!!
So I've read a ton of this site, ordering my TF-100 test kit, stopped adding "pucks" (been adding liquid chlorine at the moment) and mostly just trying to get my arms around this.
To better understand my CYA level, I diluted a sample (4 parts bottled water, 1 part pool water) and had local the pool store (Leslie's) retest it for CYA. They now claim a CYA level of 99. This fits with what I've learned of the house. It seems the previous owner has been absent for nearly a year and a "friend" has been taking care of the pool - I suspect that "care" has included Dichlor and Trichlor by the truckload...
So, it seems a drain and refill is in my future. The kid behind the counter at the pool store seems to think that I should _not_ do that this time of year. Went on and on about how the sun is going to ruin my plaster... Anything to that or just more "high quality" advice from "pool store professionals"?
So, I have other questions...
First, why is it not green? Not that I'm complaining, mind you Given a CYA of 500, If I'm understanding the "Chlorine-CYA-Chart" correctly, my minimum FC is 37.5 - no way do I have that much. I've added 3 pucks and 1 gallon of 10% since I closed on the place three weeks ago.
Is the OTO test telling me anything useful at this point? Before adding the liquid, I had barely a tinge of yellow. I interpreted that as effectively zero FC. After a half gallon of 10% and a couple hours of pump time (during the day) it registered about 2. (I added the other half the next day when the test waa showing near zero again.)