9 kg of soda.
Citric acid wash for pools.
Pour water over any remaining.
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.
For citric acid for pools.
If it works an acid wash would be a good next step.
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.
Apply soda ash to the acid puddle scrubbing the mixture with a pool brush.
Use a half a pound of vitamin c for every 10 000 gallons of water.
Dispose of what you pumped as the acid can kill frogs fish and plants.
Spray down the sides of the pool and make sure the entire surface is wet.
A citric acid wash is most effective on a swimming pool that has been cleaned with all debris removed after it is drained.
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.
Pump the mixture into a bowl using a submersible pump.
Fill the can with 1 gallon of water and then add 1 gallon of citric acid always in that order.
In your five gallon bucket add one gallon of acid to one gallon of water never the other way around.
Rinse out the bowl.
4 1 out of 5 stars 105.
The acid wash is applied from a watering can used for flowers.
Mix it gently with a mixing stick if you need to.