Now this is interesting and helpful...I have ordered a tiny stir bar, but the last time I used one smaller than the 1.5 inch one that I use for home brew starters, it kept throwing it. I suppose the screws work because they are not magnetized, but the small magnetic stir bars for what ever reason seem to be thrown easily by my potentiometer-PC fan-HDD magnet setup.
This is also interesting. I have read elsewhere, on the site I believe, to assume that the CYA is 20 if the dot doesn't disappear. I added enough liquid stabilizer assuming that the CYA was 20 to raise the CYA to 50 ppm. It now tests as what appears to be 45 ppm, but I have used trichlor tabs and dichlor shock so it is entirely possible that the CYA was indeed zero (which means it disappeared during winter...it was 80, down from 130, when I closed the pool).
There has been another interesting development. I was so frustrated that I decide to pull the fiberglass (I guess) steps out of the pool. I paid my younger brother in law to do this a week ago when I went out of town for a couple of days, as well as some other maintenance, since I have an arm injury that is on the mend and its difficult for me to lift anything bulky or heavy. When I pulled the steps out, which I shouldn't have done but powered through anyway, large chunks of algae peeled off and a ton of leaves along with it immediately floated throughout the pool. I scooped as much as I could out, raised the FC level to 27 ppm, and called my brother in law. He fessed up to not actually removing the steps, so the likely source of my recurrent algae has been discovered.
I did the 10 ml test after four hours sans the screw, and the FC had dropped to 17 ppm. I raised the FC again and brushed the pool at 6 PM. I vacuumed the pool at 8 pm. 6 hours later, and the FC has only dropped 1 ppm according to the FAS-DPD test. I've now raised the FC level to 27 ppm again and brushed the pool as well as the skimmer inlet and the return. I THINK I may have it whipped.
I am entirely uncertain as to why the first two FAS-DPD tests falsely indicated a high level of FC, but I'm comfortable in stating that I was correct in my skepticism. This go-round, when the FC was at 17 ppm, the OTO test turned a very dark (almost brown) color. I did that test because I cannot vacuum the pool properly without getting in, and I don't particulary like exposing myself to high levels of chlorine. I assumed the chlorine would be 5 ppm or less given the sunlight and the amount of algae that had floated throughout the water, but it was still much higher.
The good news is that my water is clear, and I think I've finally got everything sorted out. My younger brother in law will be doing lawn work for the foreseeable future to pay for the chemicals I wasted as a result of him having lied about pulling the steps and scrubbing them with bleach.