Thanks for the quick reply. I'd say based on that link I'm between 9ppm and 13ppm. It's definitely bright yellow but no orange tone. I will run the filter again overnight and check tomorrow. Another quick question. Trying to not raise the electric bill too much. Is it ok to only run the filter at night once the levels are ok and then after swimming on weekends (we usually swim after work and summer camp and when we get out I run the filter until morning. Thanks again for all your help!