Filter Update:
I would have put SLAM Update, but I am more focused on making sure my filter is working before I continue. I have been adding bleach, but enough to keep it well above zero and not continuously testing it. Today I took the filter completely apart. I checked all the laterals and the vertical pipe and there is absolutely nothing wrong with them:
The only slight irregularity was the scuff on this one lateral, but it doesn't appear to be broken in the least bit:
So, where I might have ultimately gone wrong:
Remember about six pages ago I said I had many years of unsuccessful pool years, and that I had pool store after pool store tell me what it could be? Well...
At some point I remember replacing all the sand in the sand filter by myself thinking that it needed to be replaced every year, and at that point I would have been a couple years late. So I dumped it all out and replaced it with random Walmart sand (or Lowes sand, I don't remember) regardless of what size it was or how much I put it. So, that could quite possibly be the root of a large % of my problems. Also, when I took the assembly out of the filter I noticed THREE of the fingers were off the assembly and laying randomly in the sand. Could they have come off when I was getting the sand out, or were they off this whole time? I'm not sure, but I have triple checked putting them back in to ensure that they are completely on there all the way.
Since the assembly is in perfect shape, I'm going to hunt for 250 lbs. of silica #20 sand or somewhere that has .45 ppm to .55 ppm sand and come back + fill it up today (based on what my filter says to use and that's the kind of sand the other threads in this forum said to use, correct me if I'm wrong please!).