Black algae in pool water can be one of the most difficult types of algae to remove. This is because unless you kill it at the root, it will sprout new heads and continue to grow. Today we’re going to look at how to finally get rid of black algae and make sure it doesn’t come back.
Unfortunately, black algae can grow even if disinfectant levels are within their best range, due to the protective coating each head has that prevents chemicals from entering its pores. It will appear as black, or bluish/green, and generally more common in plaster or concrete pools.
If you are absolutely sure that you have black algae, here are some steps you can take.
This method is for concrete or plaster pools. Do not attempt this treatment with vinyl pools or you will do a lot of damage. Below is another method for vinyl pools.
First, you will need a very stiff pool brush that you can use to brush the affected areas. Also, you will need chlorine tablets and any general purpose algaecide.
Start by making sure your pool pump is turned off, and brush the affected areas to get rid of as much as possible by hand.
Then, using the bleach tablet, apply a spot treatment to the areas. Once you have sufficiently treated each area, apply an all-purpose algaecide to them. Let it rest overnight.
The algaecide doesn’t actually harm the black algae, but rather helps remove the barrier on the heads that prevents the chlorine from doing its job. So by using the algaecide, your chlorine stain treatment will be more effective.
The next day, brush and vacuum up all the dead algae. Repeat if necessary.
For vinyl pools:
Vinyl pools are much easier to treat when it comes to black algae. You will want to shock treat and keep chlorine levels at the shock level while the treatment is taking place.
Brush the algae spots every day until they are gone. It may take several days as this guy is very resilient, but keep it up and your problem will be solved!
