If the yellow is very light, then you need chlorine. Add some bleach so your pool won't turn green.
On the pH test, is the red darker than the darkest one on the tester (which for most kits is 8.2)?
What did you decide. Are you going to use the Super Simple Recipe we linked in one of the posts above or just use bleach. We need to know so we can give you better advice.
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