Understanding Phosphates in Your Pool Water and When to Use a Phosphate Remover

If you’re a homeowner who owns a pool, chances are you’ve heard that phosphates in your pool water are bad. But are phosphates really bad for your pool? And do you need to purchase a phosphate remover?

Today, we’ll take a deep dive into phosphates, including what exactly they are, if they pose a problem for your swimming pool, and the pros and cons of using phosphate removers. Let’s get started!

What Are Phosphates?

Phosphates are chemical compounds that have phosphorus, an element that’s naturally occurring. Phosphates also have amounts of oxygen and hydrogen, in addition to other factors. These are inorganic materials that can potentially cloud your water, depending on your pool water levels.

How Do Phosphates Get into Swimming Pools?

If your swimming pool is outdoors, like most swimming pools are, you’ve got to remember that it’s exposed to the elements. That means your pool gets plenty of sunlight and also deals with rain and other contaminants — like fertilizer or landscaping chemicals — that are introduced to your swimming pool through run-off. Even leaves in your pool can add phosphates.

It’s possible for pool owners to accidentally add phosphates to pool water if they’re using chemical products that have phosphorus materials or phosphoric acid.

How Do I Know If My Phosphate Levels Are Too High?

Ideally, you’ll want your phosphate levels in your swimming pool to be under 100 ppb (parts per billion). You can use a testing kit to find out exactly how much phosphate is in your pool, but you can also tell if your phosphate levels are too high by examining your pool visually.

Although these might not be signs of solely high phosphate levels, your swimming pool might have too much phosphate if you notice:

  • Poor water quality (green, cloudy water)
  • Debris floating in your pool
  • Slimy surfaces

So, that being said, are phosphates really a problem for your swimming pool?

Are Phosphates in Pool Water a Problem?

This is the $100 question, isn’t it? After all, you’ve probably heard pool chemical stores claiming that you can control algae blooms only by eliminating these “harmful” phosphates from your swimming pool water. Algae needs only a few things to thrive: water, sunlight, air, and (you guessed it), a source of nutrients, like phosphates.

Well, it depends. It’s true that phosphates do pose an issue in natural bodies of water — like lakes and streams — and sources of drinking water, as these phosphates encourage algae growth. Luckily, your pool isn’t a source of drinking water, and it’s not a lake or stream either.

Although it’s true that algae gets nutrients from phosphates — and that the more phosphates your pool water has, the quicker the algae will grow — removing these phosphates won’t get rid of an algae issue.

If you’re considering removing the phosphates in your pool to keep algae from growing, forget it. These phosphates aren’t harmful or toxic. If algae is your pool’s issue, use an algaecide regularly, and shock your pool at night for the best effects. You’ll also need to keep those chlorine levels in check, too. However, a phosphate level of under 100 ppb is perfectly fine.

Because you’re a pool owner, chances are you’re already using a sanitizer like chlorine in your pool, which makes it an inhospitable environment to algae. If you also use an algaecide as recommended above, the chances of your swimming pool developing an algae bloom are lowered even more.

You can also do your best to keep your pool clean, which can do wonders for preventing phosphate buildup. When you brush your swimming pool on a regular basis, it prevents algae growth.

If you’re considering adding a phosphate remover to the mix, just know that it’ll be another chemical you’ll have to spend money on. So are phosphate removers worth buying? Like most subjects, there are advantages and disadvantages to using a phosphate remover.

Pros and Cons of Using Phosphate Removers

Phosphate removers aren’t always the answer. Here are some pros and cons of using phosphate removal agents.


Possibly the most apparent benefit of phosphate removers is that many have the capability to lower your swimming pool’s phosphate levels to almost nothing.

Many phosphate remover products are compatible with sanitizers, pool surfaces, and filters, but definitely check your specific brand and product before use. It’s also beneficial to know that many phosphate removers are also non-toxic. Some of these phosphate remover products can even clean the filter and waterline, too.

As opposed to other pool products (like chlorine shock), you’ll be able to use your swimming pool right after adding a phosphate remover, since they’re not toxic.


One of the primary cons is that phosphate removers can actually be toxic, especially when considering their environmental effects.

Lanthanum, one of the most popular active ingredients in phosphate removers, is moderately toxic to some living organisms, so if you’re looking for environmentally friendly ways to take care of your swimming pool, phosphate removers might not be the answer.

Another con of using a phosphate remover is that this product won’t help you if your pool water is looking green (especially if it looks green as a result of algae).

In other words, phosphate removers won’t eliminate algae. To do that, you’ll have to invest in an algaecide or improve your chlorine levels.

Finally, if you do add a phosphate remover to your swimming pool, you have to add it when your pool is balanced, clean, and doesn’t have algae.

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Preventing Phosphate Buildup without a Phosphate Remover

So, what do you do if you want to get rid of your swimming pool’s high levels of phosphates, but you don’t want to purchase a phosphate remover? What then?

One of the best methods for preventing excess phosphate growth is to take care of your pool as best you can. Balance your chemical levels on a regular basis (pH, chlorine, alkalinity levels, etc.). If you live in an area that’s constantly sunny and you have high phosphate growth, you should be brushing your swimming pool regularly (at least weekly) to prevent algae buildup too.

If you ever see things like bugs, sticks, leaves, frogs, or other debris, get rid of it as soon as you notice it. In order to be more on top of eliminating waste as quickly as possible, empty your pool’s skimmer baskets regularly. This will help you get rid of that harmful junk quicker while also encouraging water circulation.

On the other hand, if you’re ever doing lawn work outside, be very mindful of your surroundings. You don’t want grass, fertilizer, or other debris ending up in your swimming pool and contributing to the high phosphate levels.

Although it’s entirely up to you as the pool owner if you want to use a phosphate remover or not, it’s essential to realize that there are other options — from algaecides to chlorine to other sanitizers — so don’t feel boxed in by the idea of a phosphate.

The bottom line? Phosphate removers aren’t necessary for the success of your swimming pool. No matter what you choose, the most important thing is that you’re getting the most out of your swimming pool and not letting algae get in the way of your fun.

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