Can leaves stain a vinyl liner? We always open to leaves in the pool since we have so many trees. However this year I can’t get a light lime colored green into out of the pool. First time this ever happened every other year I got the pool crystal clear in less than 2 weeks

Water Test Results
FC – 5 ppm
CC - 0
PH - 7.6
Alk - 90

So far I’ve removed all matter from the pool, shocked it 2X, ran filter 24 hrs. for 2 days.
I’ve read the suggestions on staining and willing to give that a try but would like to know first if this is the logical next step. Thanks!

Other information
Pool is 12 yrs. old, 45X25 with a “L”, 40,000 gal, Blue vinyl liner (original), DE filtered, gas heated (heater not turned on yet). We get so much rain I can count on one hand the times I’ve added water – no non-rain water added this year. I use pucks until my stabilizer is where I want it then use liquid chlorine or bleach. I test and adjust my water. Last year had the pool closed and they added Algaecide, I tell them not to add any chems. If it’s metal staining only 2 things I can come up with is possible copper algaecide used or corrosion from the pool heater.