At this stage of the game, I have to wonder, why not replace the water? I would not fight something for this long that is for sure. It is July, the year is almost over, and to still be trying to open the pool is insane. Empty the pool, and change the sand in the filter, and refill it.

I don't know how some of the people would feel about that here, but that is what I would do. I am really interested in using the plastic tarp method by separating the good water from the bad and replacing the water without draining it.
If you have a fire hydrant near you, then use that to fill it , and go rent a two inch pump to drain it. The plastic should be like ten feet or so larger each way than you pool.

Good luck, I know it sucks fighting this stuff, and this is the first year that I did not have to. I closed the pool right last year, and it opened up perfectly this year. Cloudy for two days, then pristene clear ever since using bleach.