Mineral and metal stains.
Black spots on vinyl pool liner.
Maintain proper pool chemistry levels.
If the stain is on your vinyl pool steps try jack s magic step stuff.
If you do it right you should not have any black stain problems and will be able to keep your pool clean.
If the stain doesn t lighten up gets darker or the color changes to black it s probably a metal stain.
To confirm it s a metal stain get a vitamin c tablet crushed up acsorbic acid put that in a sock and place it on the stain.
Vinyl pool stains can be removed with acidic stain removal products like stain free or a stain remover or jack s magic blue stuff for vinyl liners.
Brush every black algae spot with a steel bristle brush to remove the protective layer.
For a semi bad part.
The stain colors range from yellow to brown to black.
Those pesky little spores stick to the cloth and hop off in the pool the first chance they get so be sure to use bleach to clean them.
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 can get into your pool several ways but one of the most common is from swimming suits that have been in the ocean source.
You can also use about 1 2 lb.
Of calcium hypochlorite granular chlorine in an old sock to put on a spot.
Alga spores may always be present in your pool but problems arise when the right conditions are present and the algae are able to bloom.
Bacteria sometimes show up years after a pool has been installed.
Depending on the type of stain different treatments are required to correct the problem.
Metal staining and black algae.
Black staining that appears on vinyl pool liners can originate from a number of sources and primarily falls into two categories.
We think the bacteria can be washed into your pool area by flooding rains or when a septic tank overflows.
Of all the alga types and species on the planet black algae can be the most difficult to treat and most resilient to remove from a swimming pool.
They are telling you that something somewhere is not alright.
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.
Copper iron and manganese may be introduced into the pool via source water.
Too much copper iron calcium or salts can all result in vinyl liner staining or marks.
Find the problem and work on it using the methods discussed here or find yourself a self cleaning pool.
5 10 minutes max.
Don t leave the chlorine on the spot for too long as it may bleach the liner.
Black algae in a vinyl pool is possible but not very likely.
Of calcium hypochlorite granular chlorine in an old sock to put on a spot.
Algae are diverse simple plants that thrive in water.
If the stain lightens from a small application of chlorine on it the stain is organic in nature.
