Algae require a high ph level in order to thrive so you should find that the ph levels are a bit high.
Dark spots on vinyl pool liner.
Jack will be vinyl liner blue stuff a powerful sequestrant that prevents and removes stains on vinyl pools.
If your pool has a dark surface you may need to skip this step as it could cause discoloration.
If the stain lightens from a small application of chlorine on it the stain is organic in nature.
To remove persistent staining put a chlorine tablet into an old sock along with a few rocks and put it on the stained area.
If the stain is old or excessive then the pool may have to be shocked to remove the stain.
Repeat until the black spots go away.
To get rid of the stain start by using a nylon brush to brush the spots and open up the coating.
The size location and color are important to identify the cause of the pool stain so you can properly identify and stop the source.
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.
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.
The spots are black or blue green with raised heads not free floating.
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.
Then scrub the spots again.
Too much copper usually results in blue green staining while iron results in.
For many vinyl liner stains the prescription from dr.
Too much copper iron calcium or salts can all result in vinyl liner staining or marks.
Step 2 check the ph levels of the pool with the test kit.
It could be just one small pot on the water line on steps or on the floor of the pool.
Vinyl liners can stain in localized areas and spread throughout the pool surfaces.
Bacteria sometimes show up years after a pool has been installed.
Brush every black algae spot with a steel bristle brush to remove the protective layer.
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.
Black algae will often appear on the pool liner as a series of small black spots.
Mineral and metal stains.
The stain colors range from yellow to brown to black.