I did the acid wash (and discovered a bunch of debris under the square grid inside the cell tube). Put it all back together and reset, and it seems to have eliminated the check cell lights. Thanks! Still reading low salt @2300ppm (yup,up 100ppm? I did add a cup or two of salt last night, but being that 100lbs is what I'd need, I can't see how that would have made any difference at all.

The pool store has a rather complicated looking array of beakers and tubes. One of them has a motor that spins a device on the bottom, and they drop a plastic "pill" in while adding chemicals. There's a few other beakers they use, along with a device that looks a bit like a scale with an electric meter on the bottom (I'm guessing this is the salt test by testing conductivity?)

The salt I bought is "Salinity Fine Grain Pool Salt W/Stain Inhibitor 40 Lb. Bag" so I think I'll put half of that in tonight and see where I end up tomorrow for a salt reading. I think I read too much salt can seriously damage things, is that correct?

I think I'm on the right track, anyway. Thanks for the help!