Thanks! Just want to give an update and make sure I am following your advice correctly.

Sunday night I raised my chlorine level to 30ppm using bleach. I brushed and then vacuumed the pool and it looked great. I then tested the water again Monday fc=28, Tuesday fc=25. Today, I noticed that there are traces of algae on the pool walls. Ugh!

My water tests today:

FC=21
CC=0
PH=7.4
ALK=110
CH=600
CYA=100+

I am going to add more bleach and brush the sides again to hopefully knock it out for good. My filter pressure has not risen very much at all. Should I backwash anyways?