The problem with algae

The problem with algae

Did you know there are over 20,000 known species of algae? And they just love sunlight. So that means pool owners really need to keep on top of algae in order to maintain a sparkling clean pool.

Algae are a group of non-flowering plants, which appear in the pool as green, brown, yellow or black slime often resembling fur. It thrives in corners and steps where water circulation might not be as thorough as elsewhere in the pool.

When you brush algae from the pool surfaces, some will immediately flake off while a fair bit remains stubbornly attached to the plaster, appearing as a stain. It is fairly easy to brush algae from smooth surfaces, such as fibreglass, but very difficult to brush it off rough plaster where is can burrow in the cracks and crevices.

Unfortunately, algae can have an impact on the water chemistry components themselves. For example, algae can break down bicarbonates in water, raising the pH significantly and adding alkalinity at the same time.

So what types of algae are there?

• Green algae
  The most common algae is green in colour and grows as broad slime on the pool and spa surfaces. It will first be seen on steps or in pool corners in very small patches and it can quickly grow out of control under the right conditions. The slime can be removed by brushing, but that doesn’t kill the plant. Superchlorination, combined with other procedures, will solve most green algae problems.
• Yellow algae
  This at times appears brown or muddy in colour and is also called mustard algae. It doesn’t grow as rapidly as green algae, but it’s more difficult to treat. It grows with the same broad, fur or mould-like pattern as green algae. Brushing has very little effect, although it will remove the outer slimy layer, exposing the algae underneath to chlorine. As with green algae, the best treatment is superchlorination combined with remediation techniques and good maintenance.
• Pink algae
  This isn’t actually algae, but a fungus. It appears as a reddish slime at the water line. It is easily removed with brushing and normal sanitising.

How is algae prevented?
Proper chemical balance and sanitiser residuals will prevent many opportunities for algae to bloom. High pH and low chlorine (or other sanitiser) can give algae a great start to genesis. General cleanliness of the pool is also important. Regular brushing of seemingly clean pools prevents dirt from harbouring in the pores of the plaster, which is a good start for an algae colony.

The use of algaecides is recommended to provide a back up to normal sanitation and filtration processes and is completely necessary for many pools. Swimart stocks a range of algaecides from Aqua-Health and can give you information on which products will suit your pool and how they are to be used.