Repeat until the black spots go away.
Dark spots on vinyl pool liner.
Brush every black algae spot with a steel bristle brush to remove the protective layer.
Nylon brushes will not work.
If you have a vinyl lined pool do not use a wire brush as this can tear the liner shock or super chlorinate the pool using granular chlorine also known as calcium hypo chloride.
Black algae will often appear on the pool liner as a series of small black spots.
Too much copper iron calcium or salts can all result in vinyl liner staining or marks.
If you have black or grey cloud like stains on the floor of your in ground vinyl liner they are most likely caused by bacteria that is living in the ground under your pool.
If the stain is old or excessive then the pool may have to be shocked to remove the stain.
And while a vinyl pool is not nearly as susceptible to algae if you happen to notice an infestation a softer bristled brush can be used.
Then scrub the spots again.
If your pool has a dark surface you may need to skip this step as it could cause discoloration.
Beware this works great on plaster pools but don t try this to remove stains on a vinyl pool because it could remove the liner pattern.
For many vinyl liner stains the prescription from dr.
Vinyl liners can stain in localized areas and spread throughout the pool surfaces.
Algae require a high ph level in order to thrive so you should find that the ph levels are a bit high.
Mineral and metal stains.
To remove persistent staining put a chlorine tablet into an old sock along with a few rocks and put it on the stained area.
It could be just one small pot on the water line on steps or on the floor of the pool.
The spots are black or blue green with raised heads not free floating.
In most cases this is all that is needed with vinyl pool liners.
If the stain lightens from a small application of chlorine on it the stain is organic in nature.
To get rid of the stain start by using a nylon brush to brush the spots and open up the coating.
The stain colors range from yellow to brown to black.
For metal stains either stain solution 1 the iron cobalt spot etching stuff or 2 the copper scale stuff may be indicated depending on the metals discovered.
Bacteria sometimes show up years after a pool has been installed.
Too much copper usually results in blue green staining while iron results in.
