I saw this thread and am interested in resolving my multi-year battle with mustard algae. I looked for the thread mentioned in the China Shop, but didn't see it.

I have been shocking my pool for a month in between rains and if I don't keep the chlorine about 25ppm, the algae comes back in a day or 2. Last week I had the pool covered for 4 days while it rained and it set me back from seeing the bottom of the pool, to not being able to see the bottom step.
The pool has been clearing back up, and can see the bottom of the shallow end, again.
I've been lowering my TA by adding acid and aerating, which is working.
When I opened it after the 4 days, I could see the mustard algae on the steps before I vacuumed.