For the most effective metal pool stain removal follow these steps.
Citric acid treatment for pools.
It does not harm a pool to have such a thin layer removed it simply clears away the stain.
This is how you use a large amount of ascorbic acid to treat staining in your entire pool.
Depending on the pool size and stain size another method besides treating the whole pool with citric acid is to treat the stain directly that is fill a literal sock with citric acid and put it directly on the stain initially with circulation off.
Keep in mind that ascorbic acid is best for treating iron stains while citric acid is best for treating copper stains.
Run your filter for at least 1 hour.
Treat large stains by adding ascorbic acid to the pool water by sprinkling it evenly over the surface of the water.
Start by using a 1 2 pound of ascorbic acid per 10 000 gallons of water in the pool.
Citric acid removes the stained area of a pool when applied by eating away the top layer of the pool s surface.
For tough stains sprinkle ascorbic or citric acid directly onto the spot.
I cover using bulk ascorbic acid and also using natural chemistry stain free which is citric acid.
If you don t overcome it pretty quickly though you may need to shock the pool since keeping the chlorine at low levels for very long will allow algae to bloom.
The polyquat the citric acid and the metal sequestrant tend to cause high chlorine demands so you may have to supplement the swcg with bleach to get the chlorine to register at first.
This is a good treatment if your pool has a lot of staining and the spot cleaning is not an option.
Your best bet might be to empty the pool clean it out and start over.
My pool has some staining on the steps and some of the walls.
Deactivate excess metals with a metal reducer like metal free or metal klear add a 1 2 pound of ascorbic acid per 10 000 gallons or water.