I live in Houston, TX, and we had a new pool built in later 2013. The first year was great. I followed the PB and pool store's instructions and had really no problem. Given our weather, I never closed the pool. Using an automatic chlorinator with Trichlor tabs, I kept the tabs stocked and tested with the little Rainbow test kit.
But I noticed that I was starting to see algae growing on walls and steps in April. I shocked the pool and brushed the pool repeatedly, and the stupid tests always showed my chlorine was off the 1-3 chart. The pool store told my wife that the water tested fine and that I should add 4-5 pounds of shock. Instead I searched around and stumbled on this site.
Now armed with the TF100 test kit (delivered today), I come up with the following results:
FC = .5 or 1.0
CC = 0
TA = 120
CH = 300 ppm
PH = 8.2 or higher
CYA = 90 or 100.
The pool water is actually clear, but I have seen some small swimming bugs.
The filter pump runs from about 11 am to 7 pm daily.
I tested the CYA three times. Granted, it's raining here and so I did the test inside. But whether I do it in direct or indirect light, I still end up around 100.
I'm about to add some muriatic acid to help bring the pH down. I turned the automatic chlorination to "Off" because I'm worried about the CYA going higher.
I've got approx. one gallon of bleach on hand and know that I'm going to need more to get the FC up.
What should my first priority be? Should I be adding fresh water (the pool has an overflow drain) to try to bring the CYA down? Do I bother adding bleach before getting the pH down?
Thanks in advance for your help. I'm already amazed by the help others are getting on here and have been reading the various SLAM progress reports with great interest.