Hi all. OP here, with an update. As posted before, my phosphate was quite high, in the 800-1000+ range. I ordered 2 quarts of the Clorox phosphate remover as suggested, and added it slowly over a couple weeks. No problem with the filter or clouding. But zero impact on phosphate level also. Still very dark blue using the K-1106 kit. I waited 2 weeks after treatment to re-measure. Very disappointed in that product.

Needless to say, I still have the mustard algae. It comes back every 1-2 days after brushing. With the very hot temps here in North Texas, it's been a little worse than usual.

Anyway, I'm looking for new suggestions on a phosphate remover that actually works, so we can continue this experiment. My local pool store has several products, but I'll defer to the experts here.

Thanks,
Mike

P.S. I've been maintaining FC in the 6-10 range. Here are the latest numbers:

FC=9.4
CC=0
pH=7.7
TA=75
CYA=37
CH=230
Borates=50