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Wednesday, January 4, 2012

Basic Algae Fundamentals

Basic Algae Fundamentals

Algae are a type of plant life that blooms everywhere.  In swimming pools if given a chance, they are a nuisance that consume sanitizer, raise pH and give an uninviting appearance to swimmers.  They can stain swimming pool surfaces if not treated quickly and become more colonized and harder to remove.
We most often see green algae, black algae and mustard or yellow algae in swimming pools and spas.  I have often seen combinations of these in a pool that has had a lapse in chemical maintenance and/or housekeeping.  Algae can be introduced into the water by environmental factors of anything or anyone that enters the water, drops in the water, or blows over the water.  Infestation can be welcomed by improper by sanitation levels, improper pH, and lack of algaecides.  Phosphates and also nitrates that can be introduced into the pool help to feed the algae.  Nitrates can be introduced into the pool by a simple summer thunderstorm with lightening.  You may be unaware that a cleaner you have purchased for the pool may contain phosphates. 

The best way to combat algae is to use preventative steps.  Be sure you brush the pool often to prevent the algae from attaching to a wall.  Keep organic debris out of the pool by checking your skimmer and pump baskets often as well as cleaning leaves and dirt out of the pool.  Robotic cleaners are a great help in keeping the pool wall surfaces scrubbed and cleaned.  Regular testing of pool water and the addition of proper sanitizer, preventative algaecide and flocculent helps combat algae from blooming in the pool water once introduced.

However, if you do see algae it is best to treat immediately.  Test to see what your free available chlorine residual is.  If the level is low then a shock treatment may kill the algae bloom.  Remember to watch your pH and keep in the proper range so that the chlorine is effective.  However if this does not work a use of an algaecide may be needed.

Many forms of algae have a covering that helps to protect them.  Algaecides help to break open the covering so that the algae cells can be destroyed.  Quat type algaecides do this very well for green algae and are effective in all types’ pool sanitizers including biguanides (Baquacil).  They are not effective in penetrating the cell membrane of yellow or black algae.  However they can cause foaming if more is added than is needed to perform the job since they are also a surfactant. 

Surfactants make the water wetter and break up any air bubbles that may be between the pool walls and the treated water therefore allowing the treated water to come in direct contact with the wall.  This makes quat algaecides a wonderful preventative algaecide as well.

It is not recommended to use a quat type algaecide in a spa or in a pool with fountains or waterfalls as this can increase the foaming.   Polyquat type algaecides have been developed for use in pools with fountains or waterfalls as this type of algaecide does not foam.  Polyquat algaecides are very effective at penetrating the cell membrane and also coagulating the algae for easier filter removal.   Be sure to follow the label instructions for use on all products.

Sometimes algae are resistant to the above treatments such as in the case of yellow (mustard) and black algae.  These algae form a formidable shell around them and require a more diligent treatment.  Metal algaecides such as copper and silver are best used for this type of tough algae.  Care needs to be taken to follow the proper instructions.  An abundance of metals in the presence of chlorine can cause staining to occur.  Many metal algaecides are now chelated so that staining does not occur.  This is true if there are no other untreated metals in the pool water.  Always test to see if there are metals present before treating with a metal algaecide.  If not using a chelated metal algaecide be sure to use a sequestering agent after treatment to remove the excess metals and prevent staining.

But what if the algae just keeps coming back or you just can’t get the pool cleared again?  Algae can also be caused by a lack of sanitizer due to a biofilm being present in the water such as water mold or pink slime.  Biofilms are organisms that are held together with a gooey substance that adhere to wet surfaces or are in wet environments and free floating.  Dental plaque is a biofilm but we are concentrating on pool water. Water mold can be an icky white-grey matter in the pool.  Many times it looks like wet tissue paper in the pool.  It is nasty, slimy and can harbor bacteria and other pathogens.  Pink slime is as the name says pink and slimy.  These are both fungus found in the pool.  They consume your sanitizer and many times cause the algae to start.  Many times you do not see these until you have treated for the algae and you may think that it is dead algae but a good indication it is not is that you cannot hold a sanitizer level.  These biofilms form many times in areas of poor circulation.  Areas of poor circulation include many hard to reach areas such as light niches, under the treads of steps, behind vinyl pool fiberglass step strips, insides of skimmers, pump baskets and throats of skimmers.   These areas should be scrubbed periodically to remove any of the biofilm from colonizing and dispersing more of itself.

 When treating for algae it is wise to try to ascertain why it bloomed so that you can adjust your maintenance to prevent further outbreaks.


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