Wow, you have patience! Never imagined it might take 10 days! Perhaps you should post your test results from this morning for the experts here to see and they may have something else to say. I am not an expert on pools but good at observations so maybe something here will help:
1. You have a big pool, 25,000 gal. That is almost 40% more water than mine so I know it takes a lot of bleach!
2. I noticed you have a 3/4 hp pump and I have a 2 HP pump. I don't know anything about pumps but with 40% water you have a pump that is less than 1/2 the size of mine. Size matters?
3. Did you check for all possible breeding grounds for algae? I poured a bit of bleach in my auto leveler (not sure if you have one), I ran my scuppers in case any algae was in those lines, I pulled out my pool cleaner (hummer) and found light algae on the plastic wheels between the plastic and rubber and on the plastic hose where the floats hold up the line (I slid them forward and found the algae and wiped it off). Of course with your high chlorine levels I doubt you have a cleaner in the pool anyway.
4. It's been sunny and 99 degrees for the past several days here and yesterday my chlorine reading went from 16 to 6 from 7AM to 7PM. Maybe you could use a cover or something to help reduce chlorine loss during the day? Then again that might make it worse - remember, I don't know squat!
5. Are you sure what type of algae you have? I noticed on the pool calculator that mustard algae shock levels are much higher than regular shock levels.
Maybe you should post your email so each of us can make a Paypal donation to you for $5 to help??
Good luck and hang in there, I am haunted by something I read on the TFP forum that said if you don't keep at it and solve it then all the $$ and chemicals you spent up to that point is wasted.
BTW, I'm stopping at Costco on the way home tonight to pick up another 9 jugs of 182 oz bleach. Good idea about standing on the jugs to flatten them since they exceed the size of my two recycleable containers. I'll give that a try tonight.