Just to confirm what you do in the spring: Upon opening, you shock. Wait until pool is back to normal Cl. Then add MM?

I was confused because you said: "I always add the sequestering agent BEFORE I add the chlorine" but then you said "I usually have to do a stain treatment at the beginning of the year AFTER shocking upon opening."

Ok - so I'll leave the pool to a light brown tint for the winter.

You know, I don't really think the MM works as it says it does. I think it sequesters the metals, not binds to them and then you can vacuum them up. Seems like the MM lasts for a few weeks then I'm back to staining. I did not have to fill the pool once this season, so I kind of doubt I'm getting a continous supply of metal in the water. At some point, the MM must get used up or dissipates causing the original metal to fall out. My theory.

Anyway, I think the best bet is to get my CYA down so I don't have to keep the Cl between 5 and 10. But, it just does not seem to want to go away. Maybe I'll do a partial drain next season and see if I have better luck with the stains at a lower Cl (and lower CYA).