Only a 1ppm loss overnight but still green bits on bottom

I've been messing around with something in my pool for almost a week now. First it started out as reddish-brown bits that I was unable to positively define as algae (more closely resembled bacteria according to some websites). Now I clearly have algae. I am able to retrieve small (about the size of cooked rice) bits of green squishy stuff from the bottom of the pool. I'm not talking about a lot, only a handful scattered here and there at the bottom. It doesn't seem to "cling." I can easily swish the leaf rake above it to make it move so I can scoop it up. I have had CC readings of 0 consistently with the exception of one day when it was at 1 ppm

After many jugs of bleach the past few days, last night I only lost 1 ppm overnight. That was pretty good news. Almost there. However, when I looked closely at the pool bottom (at 6:30 am) I could still see green bits. Shouldn't they be dead by now with only a 1 ppm lost overnight? Why are they still green? I'll vacuum when I get home after work and I intend to hold the high FC through today and tonight. Hopefully, I won't see any loss tomorrow morning.

My numbers:

FC shocking at 15 to 20 ppm
CC 0 the last couple of days
CYA 30-35
PH 7.8 (lowered to 7.2 before shocking)
Alk 230 (not a recent number)

28' AG Doughboy
running filter 24/7
Sand filter, added DE for the first time last night (about 1/2 cup)