What is black algae

Black algae is not actually an Algae but a single celled aquatic photosynthetic bacteria called cyanobacteria which grows in clumps on the floor and walls of the pool. This bacteria can be potentially dangerous if enough of it is swallowed and can kill dogs if they drink water with it in and unfortunately, unlike green Algae it can be very problematic to remove it from your pool.When it starts to grow it looks like a bunch of small black dots or clumps of mould but because it is a cyanobacteria these may look more green/blue rather than black and they do not float in the water like Algae does. Black algae very rarely grows in pools finished in PVC liners because they don’t provide a rough surface for it to be able to attach to unlike plaster, tiled and concrete finishes.It is important to identify black algae as it cannot be treated in the same way that green algae is and it is particularly hardy and difficult to kill especially as it can burrow its way behind tiles and deep into the pores of plaster and cement. Fortunately Piscimar make a product that together with an amount of hard work and good water maintenance can combat black algae.