Not sure if this should be under chlorine or algae?

I'm still fighting to get my chlorine levels to stay high. It's a real battle, been checking 3 times a day & making slow progress. I have put in 20 gallons of 6% bleach, after filling the trash can with empty bottles, I decided to go to Menards & get the 15% LC, & have put in 10 gallons of that, thus far.

This morning readings:
Fcl:3.57
Tcl:6.8
PH:7.1

Any ideas on how to kill this algae? I have scrubbed last two evenings Should I vacuum? Can't see the bottom of the pool, 3 feet at best. I have had it on filter continuously. How about backwashing? I have a couple times for a couple minutes, do I need to backwash till foamy bubbles are done? Pressure hasn't been high on gauge. Just wondering if I'm doing things right?