As the saying goes, "Here goes nothin'."
Day 1
Time to tackle this beast. I began with rebuilding the pump. I'm 6'8" and this pump is nestled in a lovely location that makes angles and reaching the parts difficult but nevertheless, I did it.
Turn it on, water circulates, check. Now, lets dump some of this crud to waste (I realize I probably didn't have to drain it as much as I did, but I wanted to get a little fresh water in there). I drained down to just above the returns. During that time I also connected the vacuum and ran it blindly to just remove what I could. I ran the leaf rake through the bottom several times as well. After I felt like I'd done enough blind cleaning, I let the draining continue then started the SLAM process. Got some CYA going as it was zero'd out and bumped my FC level to 13 (shock level for a CYA of 30). I let this sit over night (last chlorine add of Pool Essentials 10% was at around 11:30 pm).
Day 2
Woke up to this. I'll be honest. I didn't think it would clear that quickly. I can see the bottom and I can see how poorly my blind vacuuming went, haha. FC was at 7 when I tested this morning so I quickly bumped it back to 13.
I want to vacuum the rest of the crud on the bottom but I don't like to vacuum into the filter and I can't backwash since I just added CYA. (I think I probably did that step out of order). Can I vacuum to waste and be ok other than losing a little more water volume, to get additional crud out?