OK I put 5 gals of bleach in today to shock. I also added CYA- 3 lbs. Water is beginning to clear, but mustard algae remains.

If I understand correctly, you can't overshock a pool due to the chlorine will dissipate (sp) If I was at 5, now I should be around 15. That's a little high based on a CYA of 12 (pool store told me that-I thought it measured 30 4 days ago per a pool store) Anyway added 3 lbs to help keep my chlorine up longer. i also added an algae, not poly 60, but one designed for yellow algae. Forgot the name. It said to have a ph of 7.8- 8.0 and shock the pool. I have both. I vacummed to waste the yellow mustard algae that comes back daily in the exact same places. I said in 24 hrs shock the pool again. Then the next day vacuum to waste and backwash again. I hope this stuff works. I googled mustard algae and this stuff is supposed to be very effective. It also helps to clear the dirty algae. Anyway I hope I'm doing all this correctly. High bleach has not worked thus far.