The best solution and have found (and done many times) is liquid laundry soap and a good wide tire scrub brush. The generic laundry soap seems to work the best! You can get a cheap bottle at your local $$ store. The wide tire brush is stiff enough to clean, but soft enough to not rip the liner. I put the soap into a wide angle spray bottle and sprayed about a 1 ft section at a time. Then scrub and rinse as you go. It is time consuming, but it will work to remove the stains, new algae, and restore the liner material. Most chemicals actually slowly deteriorate the liner! Also works great on the outside of the vinyl and soft side pools.
By algaecide if you can get it under there
shock the heck out of it. put 5 1lb. bags of shock for an 18ft. round pool (7500 gallons). premix each bag with a bucket of pool water and dump around the edges of pool.
To clean algae from a vinyl pool liner after it has become crystallized, use a solution of bleach and water with a scrub brush. One cup of bleach for every 5 gallons of water should be enough to clean the vinyl liner. Rinse well, then let dry before storing the pool.
what you can do in this situation depends on what is under the vinyl liner now.
no on paint! You will need to replace the liner.
With respect. You won't bother them if they don't bother you.
You could try spraying straight bleach from a spray bottle, and then rinse with either reverse-osmosis or distilled water.
No! it well rot, use pool wall foam..
Yes, replace the liner. Nothing can put the color back into plastic or vinyl or glass or steel.
There are a number of ways you could remove stains from worms on a vinyl liner. You could use cleaners.
High concentrations of chlorine can and will destroy a vinyl liner.