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Avoiding the Summertime Greens

Avoiding the Summertime Greens

By:  Devin Byrd

It’s that time of the year again. It seems almost impossible to keep the pool clean and clear. Algae is always hiding behind every nook and cranny wanting to take over your pool. Events like the extreme rainfall and pool parties can create perfect conditions for an algae bloom.

What is algae and how do I prevent it from happening?

Algae is a single-celled plant or bacteria that uses organic material as its food source. They are all photosynthetic but do have the ability to live in darker environments (see - pool plumbing).

Treating algae depends on the type of bloom that you have present.


Green algae is the most common algae you will see. When algae is not controlled, the pool will turn green and can make the pool look like a swamp. The pool will also become very slippery and unsafe for swimmers. Green algae outbreaks can happen very quickly any time the free chlorine levels in a pool drop lower than 1.0. The great news is that green algae is easily managed. Severe outbreaks (swamp like conditions) can be handled through shock treatments, brushing and algaecide. Adding a weekly algaecide and reducing the phosphates in the water will help hinder the algae’s growth.


Mustard algae will look like a yellow-ish green and will be growing on the walls and floor of your pool. Mustard algae outbreaks can become very hard to control and will spread rapidly. Mustard algae is highly resistant to chlorine treatments. Shocking a pool with an algaecide after brushing all the walls will kill it. There are times that it will reintroduce itself so repeat treatments are possible. Mustard algae will hide in skimmer throats, light fixtures and ladders. Be vigilant if you area treating an outbreak.


Black algae is the least common algae. It is difficult to kill and will leave stains if untreated. It has a root like structure that will bore into the pool surface. The best way to treat black algae is to use a granular chlorine and granular treatment. It will require a lot of granular chlorine to be left on the affected areas. Brushing will also be required.

Always be careful when treating pools and consult a professional if you have any questions.  Have a clean and clear end of summer!