Wet the sides of the pool.
Citric acid wash for pools.
Use a half a pound of vitamin c for every 10 000 gallons of water.
Bosh chemical vanish pool spa stain remover 2lbs natural safe citrus based works excellent on vinyl fiberglass and metals removes rust and other tough stains.
When you get the ascorbic acid in the water you can turn on the pool pump and let the filters circulate the water for about a half hour.
An acid wash would likely remove it you can test by lowering the water level down below the first step and pouring a 50 50 acid water mixture from a flower watering can over the step scrubbing briefly and hosing off within 60 seconds.
The acid wash is applied from a watering can used for flowers.
A citric acid wash is most effective on a swimming pool that has been cleaned with all debris removed after it is drained.
Dispose of what you pumped as the acid can kill frogs fish and plants.
In your five gallon bucket add one gallon of acid to one gallon of water never the other way around.
Rinse out the bowl.
Apply soda ash to the acid puddle scrubbing the mixture with a pool brush.
Fill the can with 1 gallon of water and then add 1 gallon of citric acid always in that order.
You will need to use 2 lb.
Pour water over any remaining.
9 kg of soda.
4 1 out of 5 stars 105.
Mix it gently with a mixing stick if you need to.
Spray down the sides of the pool and make sure the entire surface is wet.
Pump the mixture into a bowl using a submersible pump.