I'm not quite sure what environmental reasons create the perfect environment for algae, but when this situation happens, it is very difficult to control it with typical methods. When the algae first started in my pool last summer I did what the pool stores typically recommend and that is to brush your entire pool and clean your filter. This removes the algae from the sides of the pool and gets the algae out of your filtration system so it doesn't just disperse it right back into the pool. It is also important at this time to get your pool water corrected so you have the proper levels of chlorine and pH in your water. In a typical season, this usually eliminates the problem. But this year, it seemed to correct the problem for a few days but then the algae came back. I repeated the process, again scrubbing the entire pool and cleaning out the filter. The relief from the algae was only temporary. However, I realized the extra cleaning of my filter was now shortening it's lifespan dramatically.

I went through this battle for a good portion of the summer. I finally broke down and purchased 3-month algaecide. That along with scrubbing the pool and cleaning the filter FINALLY did the trick. However, the battle with algae this summer cut the lifespan of my pool filter in half. I could tell because of the reduced water flow in the pool. I typically replace my filter once a year, this year it only lasted 6 months. The extra cleaning and the algae that I could not get out of the filter pretty much ruined it.

This past winter I went to a new pool store to get my water tested.  At this store they tested for phosphates.  All the years I had been taking my pool water to get tested prior to this I had never had phosphates tested.  They told me that the phosphates in my pool were extremely high and that phosphates are what enable algae to bloom in my pool.  They went on to tell me that I should use a product called “Phos-free” to control phosphates.  The use of this product in my pool should PREVENT algae blooms from occurring.  I’m very excited about this possibility since I have had a few summers with what seemed to be an uncontrollable algae problem. 

One year later I can report that I went through a summer using this product and am happy to report that it actually works.  The Phos-Free product is quite expensive.  The smallest bottle was over $40.00.  However, South Florida had another extremely humid, hot, and rainy summer.  In the past this combination seems to indicate algae problems for my pool.  I had only a couple very small signs of algae a few times all summer.  I just added some “Phos-free” to the pool and it seemed to do the trick.

My recommendations to anyone that encounters algae in their pools:

1) Brush the entire pool, 
2) Clean off your pool filter
3) Add 3 month algaecide to your pool

4) Get your pool water chemicals such as chlorine and pH to the proper levels.

5) Check your pool water for phosphates.  Phosphates are considered food for algae.  If you keep these low, you can reduce the risk of algae blooms in your pool.  Pool stores sell a product called “Phos-Free” to control phosphate levels.  It should be put in the pool weekly during the summer.

It is important to get your pH balanced. I noticed that with the algae problem also came the unusual problem of constantly needing to add higher amounts than normal of acid to my pool. This should wipe out the algae problem after the first try and may allow you to maintain the normal life expectancy of your pool filter.