From time to time your pool might turn green, brown or maybe even black. Don’t panic! It’s most likely algae.
Algae is not in itself harmful, and it’s not a disease. However algae can provide perfect conditions for other harmful bacteria to grow and it may also put you at risk of illness, so it’s best to remove the algae as soon as possible. If left untreated, your pool will turn completely green or brown or maybe even black.
There are more than 20,000 different species of algae, but the most common types are green algae, black spot algae, pink algae and yellow algae.
Green algae and black algae or black spot are the easiest kinds of algae to remove from your swimming pool. For yellow algae or pink algae (Pink algae is normally a bacterial infection and not so much algae.) you should seek further assistance from your pool technician as there are many different removal methods.
For green algae and black spot algie, chlorine shock, using an algaecide and brooming the walls should work fine.
Black spot algae produces hard to remove black circular stains which are very difficult to remove. This is because of their chemically resistant “skin”. You will normally need to brush the black spot algae with a steel broom to destroy this hard shell.
See How to clean up a green swimming pool for instructions on how to get your water clean and clear again.