Quote Originally Posted by hannadock View Post
ph 7.3
alk 170
cya 45
tc 4.0

the tablet I bought are by Dupont sanitizer 3" chlorinating tablets
99% trichloro-s-trizainetrione with available chlorine 90% and 1% other which it doesn't say what it is

The tabs you have are trichlor, which are raising your CYA as we speak. Your CYA is at a point where you already need to keep a minimum of 3 ppm chlorine, and preferably closer to 6. I would definitely stop using them now and switch to bleach as your chlorine source. To clear up your algae, you need to add chlorine to the pool til you get to 15 ppm and keep it there, with your pump running 24/7, until the pool goes to cloudy blue. You'll need to test and add more bleach 2-3 times daily until this happens. When the algae is gone and the water is cloudy blue, then keep your filter running but you can let your chlorine drop back down to the 3-6 ppm range, but NO LOWER than 3.

Brushing your pool daily during this process will speed it up, and running the vacuum certainly won't hurt.

Janet