Black Algae

[gfritz1]

I started a post under Dealing with Stains and Metals back on May 19th . -- Help unsure if Black Algae ?After determining it is a organic stain thought best to repost under Algae . My problem is better but by no means gone. Pool liner is 14-16 years old and has some wrinkles on bottom which makes it difficult to brush . So since initial post what have done:
1.Shocked to above 15 three days with cya of around 55-60
2.Added over a quart of the Kem Poly 60 and added a second maint dose
3.Brought PH down to 7.4

The only thing that appears to be working is a daily dose of shock (cal hypo) in a sock and attachéd to my pool and spot treat areas. They do get lighter and in some cases liner is back to initial color .
Problem is based on size of pool not sure that will ever get ahead of it

Could this becoming through the back side of the liner based on age and a very wet spring? If so what options exists?

I am brushing almost every day with a scotch pad attached to a make shift holder . I vacuum every day .Run filter 12 hrs a day . Looking for suggestions . I am use to my pool being spotless and this is killing me .

Its a vinyl inground . Ready to try anything ?

HELP

[gfritz1]

Lots of reads but no replies .Guess Black Algae is difficult to get rid of