HI everyone!! I have recently fired my pool guy and I'm learning a lot about pool maintenance. I actually find it relaxing and fun until now. I had a bad case of green algae and now I have a large amount of yellow algae in my pool. I have a 10,000 gallon below ground pool and thus far I have shocked my pool with 3 lbs of hypo-chlorite sol'n TWICE. Once this past Monday and again on Tuesday. My alkalinity is within the 80-120 range yet my pH was 7.8 and my CYA was close to zero. I added Muriatic Acid to correct that. I am using a Dolphin Premier vacuum with the micron filters but the algae just disperses like dust when the vacuum runs. I've brushed the walls and the bottom as well. Last night there was a blanket of yellow algae on the bottom of my pool. Im not sure what else to do. Algaecide? New filter cartridges? more shock? By the way, after shocking the first time my free chlorine level was up to 20 ppm. Thoughts?