You've got mustard algae growing. You need higher chlorine. Without a K2006's test results, I can't tell how high. Pool store results are PARTICULARLY inaccurate on CYA levels, which is critical in this case.

1. Order a K2006 ASAP

2. Get an OTO/phenol red (yellow / red) drops, and adjust your chlorine level to the orange-ish yellow level (not on scale)

3. Post your pump make / model AND your filter make / model. Your filter cartridge has collapsed pleats, and is probably too small for your pump, making your problems worse in multiple ways.