Hello again,
I was able (finally) to find the OTO chlorine test. It is definitely an orange result...and it has stayed orange even after 5 minutes. (Does this mean my combined chlorine is also really high?)
I cleaned the filter this morning. It had a lot of green in it, but not quite as much as previously.
The pool looks very blue, no green tinge, and pretty clear (though still just a bit cloudy in the deep end). I do see about 6 circular spots of what I believe is mustard algae right in the middle of the shallow end; when I brushed them, they plumed up and dispersed.

I could not find Polyquat, without other ingredients (like clarifier) added. :-( I went to 3 different stores...Walmart, Lowes, and Pinch-A-Penny pool supply. Any suggestions? Do you think I still need it?

I await your response with bated breath. :-)
Thank you!!