All things Algae

Many pool owners have problems with algae. What is it and what can be done to get rid of it? What can we do to avoid the problem recurring?

The following may help answer these questions and help dispel some of the misunderstandings about how and why algae will appear in swimming pools.

Algae - What is it?

Algae is a small plant growth which can take on many forms and is closely related to seaweed which itself is a form of algae.

As in the case of seaweed, it can come in many shapes and sizes but for the most part algae found in swimming pools is very small and resembles moss. These tiny microscopic plants feed on nutrients contained in the water (mainly phosphates and nitrates).

The algae spores or seeds if you like, are either already present in the water, transported to the pool by wind or are attached to other debris which finds its way into the pool.

The algae plant requires only air, sunlight, water and a good supply of nutrients to grow.

They normally grow most profusely in the shallowest water and are usually found in areas around swim-outs and steps.


By removing any one of the elements mentioned above ie. air, sunlight, water or nutrients, the algae will not grow.

The simplest way of ridding your pool of algae is to remove the nutrients required for algae growth. Removing the nutrient phosphate is the easiest way to provide an environment where algae will struggle to grow.

However, they are extremely hardy little organisms and, in some cases the algae become so resistant to the normal sanitiser that treatment with an algaecide is required. There are many of these available and your local pool shop or serviceman can advise you on which is the best one for you to use.

Once the algae dies, the residue will need to be brushed from the pool surface so it can be removed by the filtration process or vacuumed out, leaving the pool clean and clear.

Keeping the pool algae free

Maintaining correct water balance and sanitiser levels and not allowing the pool to "go off", along with occasional shock dosing, will usually keep algae under control.

Add to this the regular use of an algaecide and phosphate removal program, you can be sure the pool remains clean and free from algae.

DISCLAIMER: The Swimming Pool & Spa Association of Australia (SPASA Australia) has compiled the Material contained in the publication for the benefit of readers. The Material is made available on the understanding that SPASA Australia and its employees and agents shall have no liability to the readers of the Material for any loss, damage, cost or expense whether direct, indirect consequential or special, incurred by, or arising due to, any person using or relying on the Material and whether caused due to any error, omission or misrepresentation in the Material or otherwise.