Phosphate Removers - Further Reading

Reasons for use

Phosphate Removers should be looked at as an insurance policy NOT as a required part of pool care. If a user struggles to maintain the FC/CYA ratio then using a phosphate remover may help the user avoid an algae outbreak. Algae will occur if chlorine isn't added, but with a low phosphate level it'll take longer to happen.

Testing

The goal is always zero phosphates or as low as possible. So it doesn't really matter how high they are to start with or where the test maxes out at. For the Taylor test ($11 by the way), there's a high limit version that goes up to 2000ppb but it's not necessary, just use water dilution if you max out to get a feel for where you are. Most commercial grades of PO4 removers can handle 10,000ppb per 10,000 gallons of pool water per quart of of product administered.

Taylor has the K-1006 phosphate test kit.

Using Phosphate Removers

Lanthanum chloride reacts with the free, dissolved phosphate compounds to form a salt (precipitate) of Lanthanum and phosphate (lanthanum phosphate) which is not soluble in water. The chlorine ion from the Lanthanum chloride likely ends up bound to free sodium ions to form sodium chloride, table salt, which would dissolve in water. Lanthanum sulfate is also in these phosphate removers and reacts in a similar way with phosphate.

Lathanum itself is classified as a rare earth element. It's not actually that rare in deposits, it's just fairly difficult to mine and extract, hence why phosphate removers with lanthanum compounds are relatively expensive and largely unnecessary if proper chlorine levels are maintained.

Effects when fighting Algae

When a user already has algae in their pool Phosphate Removers do very little. In fact when testing for phosphates with a green pool will result in a false result as quoted Algae in a Pool will result in a false reading. This is displayed on the instructions from the Orenda 10,000

Additionally a user may add a large amount of phosphate remover to the pool only to see phosphates return quickly once the SLAM Process is complete. This is because live algae has phosphates in the cell walls and these phosphates are released once the algae is killed. If a user removes all phosphates from their water before killing the algae there's a chance they'll need to do it again once their water is clear, thus wasting their money.

What's the best Brand of Phosphate Remover?

One of the first con’s in the past we’ve placed on phosphate removers is the price. After I purchased a phosphate test kit and found my levels towards the “high” end I started searching for the best phosphate remover to use. I found there to be a rather large difference in quality from my searching. A liter of “Natural Chemistry” will only remove 2000ppb phosphates from a 10,000-gallon pool while a product such as Orenda PR-10000 will remove 10,000ppb phosphates from a 10,000-gallon pool. Both are in the $40 range while the Natural Chemistry is sold as a 2-liter compared to Orenda which is sold as a quart. Regardless the Orenda brand is considerably the better deal……but how costly is it truly to use? For me and our 24,000 gallon pool I started out my phosphates were roughly 1500ppb, so I needed to add roughly 15 ounces or roughly ½ a bottle. Now as expected the pool became cloudy within minutes which cleared up after a day of filtering. After adding this initial does last year I’ve needed to add another dose once at the start of this season which was another 10 ounces. As I sit today I still have just over 10 ounces remaining even after 2 years of use now. If the pattern continues in our pool this means the initial purchase of a $40-dollar bottle of Orenda phosphate remover will last me roughly 3 seasons and make the product about $13 a season.