Best Way to Add CYA

[paigemetoo]

Brand is Aqua Zone
Ingredients
Sodium dichioao-S triazinetrione hydrate......... 99%
other ingredience(thats exatly what it says).....1%
Available chlorine.......................................... ..55.5%
If I can use it how much and how offten do I test?
THANKS!

sorry spelled dichioao-S wrong should be dichioro-S

oh and my chlorine is at 10 ppm. Since it is in a good range I really don't need to add any so what should I use to raise my cya? Last year was my first year using the BBB method, trying to clean up a big mess the pool store made of my pool and it was at 70 so I didn't have to add. The last thing I want to do is ask the pool store for a stabilizer and end up back where I started.