Is your pool green? Does it need a phosphate remover

11/20/2013 Scott Morris

In recent years the use of phosphate removers in swimming pools has been a hot topic and the subject of much debate. Here’s a little background on the subject.
Phosphates are a biological building block that nourish and promote the growth of plants – including algae. Phosphates are present in all natural water, which obviously includes the water in your swimming pool. The idea behind phosphate removal products is that less phosphates in the water will mean less algae. The question then becomes – do these products really work?

To be honest, the effectiveness of these products is debatable. There is one school of thought that says phosphates in pool water are not a concern unless they exceed 1000 parts per billion (ppb). The other side of the debate says that phosphate levels should be kept to a maximum of 125 parts per billion. Obviously, there is a huge difference between those two numbers.
 
My opinion on the matter is that using a phosphate removal product in your pool water is perfectly fine – as long as you follow the package directions on your pool water testing kit and don’t go overboard trying to get your levels way down.
However, I must say that I found the results of a recent study on this subject done by McGrayel Water Technologies to be quite interesting.
The study involved two one-quart glass jars of water. One jar was filled with distilled water (which contains zero phosphates). The other jar contained water with 1000 ppb phosphate added.
The jars were set out side by side in indirect sunlight for seven to eight days. In repeated tests, both jars of water grew the same amount of green algae.
You can draw your own conclusions from this, but my opinion is that if your water contains less than 1000 ppb phosphates, you probably don’t need a phosphate removal product. However, if you want to use these products there is no harm in doing so – other than the added expense.