Pool hasn't been opened for three years. Lots of algae. Help.

Start from scratch, stir the pool and agitate it as you completely drain it. Wash down the insides with a cholinated/bleach water and pump to waste, then refill.

Start from scratch, stir the pool and agitate it as you completely drain it. Wash down the insides with a cholinated/bleach water and pump to waste, then refill.

Anytime you drain a vinyl liner pool, be aware the liner can SHRINK and will NOT be usable again.

Even if it is not that old and the temps are cooler, it will shrink. Doing it on a warm sunny day may help. DO NOT allow it to sit with out water, put on fill ASAP.

And then, it still may shrink, even if another liner didn't, yours may...

If you wash it down while the algae is still wet, it comes off easier. (no real need for chlorinated/bleach water most of the time) Some stains may not come off no matter what you use.
Over time and proper chlorine levels and proper care, they may fade.

Take a day you can devote to washing/cleaning it as it drains.
Don't use straight bleach on vinyl.