Hi.
A CC of .5 means .5 or less...nothing to worry about. Depending, the yellow stuff COULD be pollen. I got tons of yellow pollen for several years, so thick it would coat my skimmer sock like butter-yellow spackle paste!

Dichlor will continue to raise your CYA level, 9ppm for every 10ppm of Free Chlorine it adds. You'd be better off switching to bleach/Liquid Chlorine or Cal-Hypo.