Phosphate Removers Explained Simply

Algae that won’t quit is usually trying to tell you something, and a lot of the time that “something” is phosphates. We dig into the real role phosphates play in pool water chemistry, why they’re measured in parts per billion, and why they don’t simply disappear through evaporation or time. If you’ve ever had a pool that looks balanced but still blooms, or you watch chlorine vanish day after day, this conversation gives you a clean, practical way to diagnose what’s happening.

We break down the most common ways phosphates enter the water: fertilizer drift, organic debris, phosphate-containing soaps and cleaners, and especially fill water where orthophosphates can be added during municipal water treatment to protect copper pipes. From there, we get specific about when it makes sense to test, what “300 ppb” really means in the field, and which testing options are the easiest to rely on, from simple strips to pool store testing and tools like the Spin Touch.

Then we talk treatment without the drama: how to choose a phosphate remover based on strength, how to dose per 10,000 gallons, and why overdosing can trigger cloudiness, heavy filter loading, and rising PSI. We also connect the dots to prevention, including maintenance dosing and the critical 7.5% free chlorine to cyanuric acid ratio so algae doesn’t reappear and make customers doubt the whole process. If you want clearer pools, fewer repeat algae calls, and a better way to explain pricing, hit play, share this with a pool pro friend, and leave a review with your biggest phosphate or algae question.

We break down what phosphates are, why they act like algae food, and why they linger in pool water instead of disappearing over time. We also walk through how to test, when to treat, how to dose safely, and how to prevent the same algae cycle from coming right back.
• what phosphates are and why they feed algae
• common phosphate sources such as fill water orthophosphates, fertilizer drift, cleaners and sequestrants
• why phosphates build up instead of evaporating or breaking down
• when algae points to a phosphate problem and the 300 ppb rule of thumb
• practical testing options including strips, pool store tests and Spin Touch
• choosing a phosphate remover based on strength and phosphate level
• dosing guidance per 10,000 gallons and why overdosing causes cloudiness and high filter PSI
• cleaning the filter after treatment and using maintenance doses all season
• keeping algae from returning by holding free chlorine to the 7.5% FC to CYA ratio
• how to explain the process and price the added chlorine and labor
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Transcript

Welcome And What We Cover

SPEAKER_00 0:14

And welcome to the pool guy podcast show. In this episode, I'm going to talk to you about phosphates. I'm going to cover what are phosphates, the effect on the pool, ways to treat pools with high phosphates, and ways to actually know if the pool has a phosphate problem or not. Are you a pool service pro looking to take your business to the next level? Join the pool guy coaching program. Get expert advice, business tips, exclusive content, and get direct support from me. I'm a 35-year veteran in the industry. Whether you're starting out or scaling up, I've got the tools to help you succeed. Learn more at Summicpoollearning.com. So, what exactly are phosphates? Phosphates are a naturally occurring chemical compound and they contain phosphorus and oxygen. And this is the primary nutrient for algae. Algae has different food sources, and I would say that phosphates are their primary food source, and therefore if you have phosphates in the water, you more than likely or g are gonna have algae in the water because

Coaching Program Invite

SPEAKER_00 1:20

there's food in that water to feed the algae. Now, where does how does phosphate actually enter the pool? This is kind of interesting because you know back when I first started there was no phosphate removers and no one talked about phosphates whatsoever, but it's becoming

What Phosphates Do In Pools

SPEAKER_00 1:40

more and more of a problem, of course, because now we have phosphate removers and we do know that phosphates are a real issue in pool pool water. There can be a number of sources where the phosphates enter the pool. If you're in a more rural area, it could just be you know the fertilizer blows with the wind, it could be a few houses over, it could be, of course, when the gardener puts some fertilizer on the grass, these all wash into the pool and get blown into the pool, and

How Phosphates Enter Pool Water

SPEAKER_00 2:12

that raises the phosphate level. There is some organic phosphates also when leaves fall in the pool. I don't think that would be the main source, nor fertilizer in some cases, unless you have a lot of, you know, if you're in an area where people are using a lot of fertilizer, but it can be airborne and it can blow from pretty far away. One of the main sources, I think, where the phosphates enter the water, this is something that Terry Arco talked about in the early days of phosphate removers, is from the treatment of water. They use the phosphates in water treatment, they introduce orthophosphates into the water supply to maintain the copper pipes that are you know in use today. And so a lot of this, you know, in my area we use well water, so we have a lot of the phosphates coming into the pool from this source. It doesn't take a lot of phosphates, they're measured in parts per billion to cause a problem in the pool. So I think the fill water is a one of the main sources of phosphates entering the pool nowadays. And of course, there are a lot of chemicals that contain phosphates, any kind of pool tile cleaner or any kind of soap has phosphates in it. And of course, a lot of the chemicals that are used to manage the the sequestering agents, I should say, for metals have phosphates as well. So logically, you think the pool has a pretty big body of water, and it's going to dilute the phosphate level in there. You know, just let's just say that you fill the pool up and some phosphates are introduced, and you're thinking, well, I mean, they're gonna eventually get out of the pool naturally. Well, in fact, they don't evaporate out of the pool like the pure water and phosphates actually don't break down on their own either. So they stay in the water and they can't grow, of course, and get higher numbers of phosphates when you do the reading, you'll get more phosphates in the water, especially when the algae is in the water. It's kind of like one of those circle of life things where the more algae, the more phosphates, and things start to get out of control pretty rapidly in the pool that has even a small phosphate level. What level should you treat the phosphates at? Most of the manufacturers of phosphate removers say 300 parts per billion is the threshold of phosphates in the water. When you do test the phosphates, and how do you test them? Well, there are various ways to test them. The test trips are probably the easiest phosphate test trips. Your local pool store can, of course, test for phosphates as well. If you bring a water sample in, the Lamotte Spin Touch has a phosphate test on their disc. So there are ways you can test for phosphates. It's not something that is not testable, and it's something where the tests have become kind of essential out there in the industry to test for phosphates. Is it kind of common sense or one of those things where a rule of thumb, if the pool has algae, it has phosphates? I would say yes,

When To Test And Thresholds

SPEAKER_00 5:20

that's probably true because you know, although there are more than one food source for algae, phosphates are one of the one of the main food sources in my area at least. And so if a pool has algae, it probably does have an elevated phosphate level of some type. A lot of times you will have your pool pretty much perfectly balanced, and you'll have a good chlorine level, but you'll still have algae in the pool, and there's a good possibility that you have phosphates in the water. So it's not a bad idea to test for phosphates at that point when you notice that the chlorine is disappearing rapidly in the pool, you're having trouble maintaining a good chlorine level, and algae is blooming in the pool. There is a pretty good chance that there is some phosphates, elevated levels of phosphates in the water. So you would get a test strip, would be the most common way to test it, and then you would read that test strip to see what part per billion level of phosphates you have in the water. So, how do you treat the phosphates in the pool water? Well, you'll need to use a phosphate remover to remove the phosphates from the pool water. Now there are two that you can choose from that I use regularly. One is natural chemistry phosphory, and the other is the Arenda PR1000. Why do you why would you use one over the other? There are differences in strengths with these products, and the natural chemistry phosphory is a weaker phosphory mover, it's not quite as potent as the PR 10,000, and you'll see this when I go over the dosing and the treatment or the the instructions for use of the phosphory versus the PR 10,000. Now the phosphory has this is all for 10,000 gallons of water, by the way. So these dosings are for 10,000

Picking Products And Dosing Safely

SPEAKER_00 7:07

gallons of water. So the phosphory, if you have 300 parts per billion or less of phosphates in the water, they want you to use 16 ounces of the product to treat that. If you're at 600 parts per billion, you're gonna use 32 ounces. If you're at 1200 parts per billion, you're gonna use 67 ounces of the product to treat the phosphate remover. Now, this is a weaker product, in my opinion, and it's something that you can use very easily out on your pool route to treat phosphates, and it does a pretty good job of treating the phosphate. You're just using a lot of product to treat it because it doesn't have the potency of some stronger ones. Now, besides the Arenda PR1000, I think the Biodex makes a pretty strong phosphorate remover, and so does C Clear. C Clear is the same company as natural chemistry, but they do have a stronger phosphate remover and they do have a phosphree max also, which is a stronger phosphate remover. But the PR10,000 would be my choice for you if you have a higher phosphate level in the pool. For example, if you have a phosphate level of 500 to 1,000 parts per billion, you would just need four fluid ounces of the PR 10,000 in the pool. If you have a phosphate level of 1,000 to 2,000 parts per billion, you you would use 8 fluid ounces per 10,000 gallons of water. And the instructions also specifically state you don't want to use more than 8 ounces at a time in 10,000 gallons of water. So if you have a 20,000 gallon pool, of course, you can use 16 ounces safely in that pool without overdosing. And believe me, you can overdose on phosphory mover, and it causes a lot of dropout, causes high filter pressure, and it causes all kinds of problems. So you don't want to, of course, overdose on the lanthium that's in the phosphorylate mover. It can have a pretty bad chemical reaction where the pool gets really cloudy, the filter pressure again rises dramatically. And part of the treatment, of course, is cleaning the pool filter after the treatment because the filter psi should rise with all the phosphates that have been trapped in the filter, and you're gonna have to clean that filter out to drop the psi back down as part of the treatment. And so, of course, you're gonna have to charge for phosphorate removal treatment because there are some steps involved besides just adding the product to the pool. So you should see a dramatic drop in the phosphate level from week to week using the phosphoryl in the pool. You're going to eliminate the algae's food source, which means that the algae is going to slowly the algae in the pool will, of course, slowly get better, disappear in the pool. Now, there are some factors, of course, that may keep the algae growth consistent in the pool still, and that is, of course, you have to maintain a good free chlorine level constantly during that that week so that the pool is sanitized. You also want to make sure that the filter is clean, so after the treatment, clean the filter. And these should all be good enough to clear up the algae in the pool in most cases. And I mentioned earlier that phosphates are introduced in the pool water, maybe through the wind, if you have neighboring properties with a lot of fertilizer, different things cause that to get into the pool out in nature, and you have orthophosphates being added when you're filling the pool. So it's not a bad idea to add a maintenance dose of the phosphorus remover and to keep the phosphate level consistently low in the pool. It really doesn't harm the pool, nor really mess up the chemistry in the pool with the maintenance dose of the phosphorylate remover. And the filter psi shouldn't rise very rapidly with a small dose of phosphorylate remover in the pool because you're not really causing any major interaction with the phosphates with the phosphorus remover to cause that kind of filter psi to increase in the pool. And it's a good idea once you discover that you have more than 300 parts per billion of phosphates in the water to add the maintenance dose all season long to keep the treatment or keep the phosphates from returning at a high level, which will happen if you don't keep the maintenance dose in the pool. And the cure, of course, is to do an initial phosphate treatment to eliminate the phosphate or to treat the phosphate at the level it's at 100,000 parts per billion, 500 parts per billion, whatever the level you're going to look at the product using, either the PR10,000 or the phosphory. And then you're going to add the dose to the level that's required, not to overdose the pool, of course, and then you'll have to clean the filter on your return visit once the psi goes up and the phosphate remover has a chance to really do its work in the pool. And at that point, you want to of course keep the chlorine level consistently high at that point so that you can treat the algae and keep it from returning. And then you'll use a maintenance dose of the phosphate remover going forward to prevent the algae or the phosphates from coming back to the pool, which will feed the algae and cause the algae growth. So it's a process when you have phosphates in the pool water, and you have to explain this to the customer, and it's pretty easy to explain. Just let them know that phosphates have gotten to the water. It could be the water source, it could be something airborne or something near your pool, it could be a product when people are swimming in the pool, but you have phosphates, and I'm going to treat it, I'm going to eliminate it. Here's the fee for this process, and then I'm going to have to charge you for a bottle of this phosphate remover to use as a maintenance dose the rest of the season to prevent the or to keep the phosphate levels, you know, at 100 parts a billion or low in the pool so that the algae won't reoccur. Now it's important that when you do all this, that you don't have the algae reoccur in the pool because the customer will be scratching their head thinking, I paid this money

Maintenance Doses And Filter Cleanup

SPEAKER_00 12:55

for the treatment, I have this person adding this dose in there, and there's still allergy in the pool. So there are some critical factors with the chlorine level that you should know about, and I talk about this often: the 7.5% ratio of free chlorine to cyaneric acid. So if the pool that you're servicing has a cyaneric acid level of 100 parts per million, you do the phosphate treatment, you raise the chlorine level up. What level should the chlorine level be at? Well, it needs to be at 7.5 parts per million to be effective in that pool if the cyaneric acid is at 100 parts per million. If you do simple straight math, 7.5% times 100, that's 7.5 parts per million of free chlorine you're going to need to maintain. So one of the dangers here is that you treat the pool and then the free chlorine level is not kept at the level it should be kept at based on the cyaneric acid level, and algae could reappear in that pool. Now it's going to be harder for it to reappear in the pool if you have the phosphate treatment going. I'll grant you that. And I consider the

Preventing Algae With Chlorine Ratios

SPEAKER_00 13:55

phosphate remover a chlorine enhancer of some in some sense and fashion because it does eliminate the food source for phosph for the algae, I should say, and it does help main to keep the maintained, allow you to keep a chlorine level and keep it maintained at a pretty good level in the pool. But you have to remember the ratios here that you're dealing with, and you do not want the algae reappearing in the pool after the treatment, because then the customer is going to question, of course, the whole process and the whole phosphate remover treatment that you did in their pool. There are also a few other costs involved with the phosphate treatment of the pool because when you first discover this problem, you're going to have to keep raising the chlorine level up to a higher level, shocking the pool, treating the algae. So there is an algae treatment that you're a process that you're going to go through with the customer. And depending on your business model, you may have to charge the customer for the algae treatment, you may absorb it, and it's one of those things where some people this does kind of work sometimes where you have a couple pools that use a lot of chlorine, but you have a lot of pools that don't require a lot of chlorine. So it kind of evens out on your route. The maintenance dose evens out. And I do believe this is true. But if the pool is a problem where you're using a lot of chlorine and you're trying to balance it, balance the water, keep the chlorine level high while you're doing the phosphate treatment, you may have to charge the customer during the phosphate treatment a higher rate to cover all the chlorine that you added prior to this. I wouldn't necessarily build them separately, but if you're normally charging, you know, 150 for the phosphate removal treatment, but you use a lot of chlorine in the process prior to this, then you can charge them 250. It's not a big deal. You want to just make sure that you cover your losses with a pool that has this phosphate problem. And this could develop out of nowhere. You may have a pool that's perfectly fine and clear, and then the next week you get there and it has algae in the pool and is losing the chlorine level rapidly as the week goes on, and you're fighting this pool, and you never had a problem prior to this. Believe me, I run into this before where the pool is perfect and all of a sudden it has this phosphate issue develop. And treating it is the only way to really solve this problem. Lowering down the phosphate level is key

Pricing The Process For Customers

SPEAKER_00 16:10

to preventing the algae from coming back. So remember that it's a process and it's a cycle, and it's something you have to explain to the customer because a lot of times they're not going to understand what you're doing or why you're charging them for it. So the process is effective and it is a process you're going to have to implement to get rid of the high phosphate levels in the pool. If you're looking for other podcasts, you can find those by going to my website, SonyPoollearning.com. On the banner, there's a podcast icon. Click on that, and there'll be a drop down menu of over 1900 podcasts you'd listen to at your leisure. And if you're interested in the coaching program that I offer, you can learn more at poolguycoaching.com. Thanks for listening to this podcast. Have a rest of your week and God bless.