Quadruple Shocked, pool still Teal!!!

Recently purchased a home that came with an above ground 26 x 52 InTEX. It was a pea soup color per instruction I skimmed out all that I could ran the pump and basically quadruple shocked it within 4 to 5 hours it turned a nice teal color. We then began filtering it with a big sand pump. It's now been 12 ish hours and there is no difference. We've backwashed and continued to skim the big pieces of algea that float to top. We've balanced the ph so to speak by bringing it down. I was hoping within week pool would be ready to go but going on day 5 and there hasn't been much improvement aside from the green to teal. (Our father in law tried a few things before shock) Should I continue to shock?! It probably sat 8 weeks before purchase with no attention