(41) 121oz bottles of 8.25% would be about 130 ppm on your pool -- that is definitely in the range of normal consumption once the pool goes swampy.

1. If your pool is covered, don't add CYA yet. If your pool is uncovered, I'd recommend installing the mesh cover, but leaving the corners accessible, if you can do this. It's much easier to clean up an algae-only swamp covered, than it is uncovered. When you're ready to vacuum, you can just unhook and flip back one side.

2. Have you been testing CC levels? If not, you should. It's possible your CYA has been converted in part to ammonia. If so, that consumes huge quantities of chlorine, during cleanup.

3. I'm sorry I haven't chimed in sooner, but I was waiting to get more definitive results on using phosphate removers in conjunction with winterization. Keeping your phosphate levels below 125 ppb during the pool season can be very difficult, since phosphates can enter the pool from multiple sources -- my own local potable water has ~2ppm or 2000 ppb phosphates! But during winter, you are NOT constantly adding phosphates, so it may be practical for you to drop your phosphate level < 125 ppb, and then be able to keep it there till spring without any further effort.

A pool with very low phosphates is not algae-proof, but it is quite algae resistant, and *should* be easier to maintain. Very likely, you can achieve that for less than $100. If you're interested, let me know. But keep in mind, I have not fully tested this method myself yet.