Algae can be a problem in pools as it grows on the sides of the pool. The algae growth will start near the water level and then advance down the pool wall.

Algae causes the walls and the floor of the pool to become slimy and slippery which can be dangerous when swimming.

Black algae can also have damaging effects on marble plaster. Algae is not really harmful to humans, but it can cause havoc with your pool’s water quality. Algae will increase the pH level of the water which will cause the sanitisers to become less effective.

A clean, clear pool can quickly be overwhelmed with algae and it will turn green. Algae spores are blown into the water daily either naturally by rain or washed in. It is impossible to keep algae out of the pool and so pool owners have to fight a battle to control algae.

Try to keep the chlorine and the pH levels right and that should control it, but certain changes such as hot weather that will warm up your pool water. This will result in reduced alkalinity, then your pH level goes out of line, chlorine levels decrease – and the algae will not be controlled anymore.

Green algae is the most form of common algae that is found in swimming pools. It can either be free floating, in the water, growing on the pool walls or in filters. If green algae is not treated, it can clog filters and transform to a permanent form on the walls of the pool. Green algae can be treated easily with a proper shocking algaecide that is powerful enough to kill the algae.

Another common type of algae can be identified as green spots that form all around the pool. Shady areas will show the green spots first and the water will remain almost clear. The algae causes the water to have a sting effect on the swimmer.

One cause of this algae can be neglect of the pool maintenance routine as the water quality and pH decreases. Treatment for green spot algae would be to balance the water and then treat the water with a large shock of chlorine and a good quality algaecide. Follow up treatment might be needed for severe cases.

One of the worst is black algae which grows in cracks and especially the plaster of pools. Black algae is typically found in concrete or plastered pools. It protects itself with a heavy layer of slime which makes chlorine useless. The water will normally remain clear, but it will cause the pool to need more chlorine than normal to remain at a satisfactory clarity level. Brushing black algae off will be a waste of time because even of it is removed, the algae will return a day later.

Treatment for black algae will be to have the water tested and receive advice from your local pool company. Before treatment, the algae must be brushed to break the slime barrier that protects the algae. Black algae can be transferred from one pool to another by using the same pool maintenance equipment and with children’s toys.

Algae will return to the same place and this could be due to a dead spot which is a place in the pool where the circulation does not reach. If this does happen, treatment will need to be started and the circulation of the pool will need to be altered to accommodate the dead spot.

With the proper chemical and constant treatment by following directions, you will be able to be successful in the war against algae.Pool pH test kits should be available from your local pool shop.