How do I get rid of phosphates in my swimming pool?

So you have phosphates.  Now what?

There are so many options for phosphate removal that it can be tough to figure out what to use.  Don’t worry, we’ve got you covered.  Answer this simple questions to find out what phosphate remover is best for your situation:

How high is the phosphate level in your pool?

Under 200ppb



Over 1000ppb



My Phosphates are under 200 ppb:

For swimming pools with phosphates levels under 200ppb most pools will not see adverse effects due to phosphates.

If your pool is having clarity issues or algae blooms with a phosphate level under 200 make sure to check out other sources of algae before putting too much money into phosphate removers.  You want to make sure you are focusing on the most likely culprit.

bioguard pool complete

A weekly maintenance product is best if you are concerned about bringing your phosphates down to zero or know your pool’s phosphates continually increase without using a phosphate remover.  The product we have been most impressed with is BioGuard’s New Pool Complete.

Pool Complete has proven to be great for not only removing lower levels of phosphates, but it is also an amazing clarifier and uses enzymes to break down oils and scum lines in the water.

natural chemistry pool perfect phosfree

If you prefer Natural Chemistry products, Pool Perfect plus Phosfree is also great for weekly phosphate treatment.  It has a strong enzyme for removing water lines, but does not have a clarifier built in.  Since many swimming pools benefit from water clarifier and BioGuard Pool Complete has worked so well for our customers since its introduction in 2016, we have revised it as our primary recommendation for weekly phosphate removal.

My Phosphates are between 200-500ppb

This is the gray area of phosphates.  While most manufacturers prefer phosphates levels at zero, we personally have not seen many adverse effects until the levels get above 500.  Usually below that number we don’t find it necessary to add a phosphate remover unless you have had a history of algae problems or continuous phosphate growth.

There is also some debate about how much more chlorine is used at this level of phosphates, but that is where the grey area kicks in.  We have not seen exact numbers pointing to the additional cost of chlorine versus the cost of phosphate removers at this level so it is possible you would be paying for one to reduce the cost of the other.

Do you have a Salt Pool?

The manufacturers of chlorine generators in salt pools are more concerned about phosphate levels so it is good to keep them lower than 200 if you have a salt pool.  In a salt pool it is better to err on the side of caution and lower the phosphates.  Your salt generator manufacturer will likely ask about your phosphates if you have issues keeping chlorine levels high enough.

Generally a weekly maintenance product like the ones above are still enough in this area unless you are already experiencing algae growth.  It is important to remember though, that phosphate removers will take out phosphates but not kill algae that is already growing in the water.  You will still need an algae killer for that.  If you are already seeing issues with phosphates, choose one of the options in the 500-1000 range below.


My Phosphates are between 500ppb – 1000ppb

In this range, phosphates can start causing pool problems like algae growth and cloudy water.  The two products that works best for these phosphate levels are BioGuard’s Pool Tonic and Natural Chemistry’s PhosFree.


BioGuard’s Pool Tonic treats up to 1000ppb with one quart, but it can cause cloudy water for up to 48 hours, so if your pool is clear and you have people coming over, Phosfree may be the better choice.

However, we have found Pool Tonic to work very well in these levels, so if the pool is already cloudy or you aren’t planning to use it for a couple days it is a great choice.

Natural Chemistry’s Phosfree is a tried a true phosphate remover.  If you have a larger pool the dosage can get high; 1.5 liters treats 900ppb in 10,000 gallons of water. It will likely need to be added in a couple doses as well, since it is advised not to add more than 1.5 liter at a time.  However, it will not cloud the pool like Pool Tonic, so if you want to keep the pool sparkling clear during treatment, this is probably the better choice.natural chemistry phosfree

Make sure when using any phosphate remover to check the filters and backwash or clean them as needed.

These products are pulling out many small particles which can clog up your filter much more quickly than usual.

After using a phosphate remover, you will probably want to invest in a weekly phosphate remover like Pool Perfect+Phosfree or Pool Complete to prevent high levels of phosphates from returning.  Pool Complete especially is great since is eliminate the need for a separate clarifier if you are already using one of those.


My Phosphate level is over 1000ppb

07200_phosfloc_4lbsWhen your phosphates are over 1000ppb you have probably already seen the effects of phosphates in the pool and likely have very cloudy water or algae already.  In these cases, you will want a serious phosphate remover.

The one we recommend is Natural Chemistry’s PhosFloc.  It settles in the water for up to 12 hours.  It will force the sediment to fall to the bottom and then is vacuumed directly to waste, pulling the particles along with the phosphates directly out of the water.  Please note Phosfloc is used for very high phosphate levels, and it is difficult to remove all phosphates in one treatment at this level.  This means you may still have some phosphates left.  These can usually be removed using a regular phosphate remover.

Phosfloc is not as easy to use as other phosphate removers, but it can take a pool from looking terrible to pretty clear in 24 hours.  It also removes far more phosphates at one time than Phosfree or Pool Tonic can.  Make sure to follow the dosages correctly so you don’t have to repeat the process.

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