Debating on phosphate removal

[Dan Morrill]

I'm looking for some advice from someone who has gone through the process of removing phosphates from their pool.

Let me start by saying I have read tonnes of threads on this topic on this forum. I fully understand that phosphate removal does not prevent algae. It's just removing a food source. At best, it makes it a bit harder for a bloom to start if your FC/CYA levels drop too low.

My phosphate levels are very high, in the 2000 ppb range. I don't have a phosphate test, so yes, I am trusting the pool store's results. But I consider them to be fairly accurate for a couple reasons. First, they are fairly consistent with my own test results on other readings. Second, I seem to have very little leeway if I accidentally let my FC levels slip. Algae tends to grow very quickly on me if I let it. This makes me think my pool water is kinda tasty for them.

I'm hoping someone who has tried this with a high phosphate number and a sand filter can let me know what to expect if I try it, and whether you felt it was worth it. I keep thinking I want to try it for the added insurance, but cringe everytime I think about the cloudy mess I might have and if the sand filter will take forever cleaning it a out.

 

[FT Pool]

I can give you my experience with partly removing phosphates out of my pool but it was with a cartridge filter. My pool has run consistently clear but with phosphates in the 4500ppb range. Like you I debated doing anything about it since I just kept up with my chlorine levels.

I decided to just give it a try and remove the phosphates. I used the Phosfree product my pool store gave me. Don’t know which one as I know there is a Plus and Max version but I dealt with a cloudy pool and daily cartridge cleanings for a full week. Phosphates are down to about 2500ppb so I know I have another treatment in my future but I do consider the process a success. (Wife says no more playing chemist with the pool until “off” season lol)

Sorry I can’t help with what your experience will be with a sand filter but I can tell you the “gunk” coming out of my cartridge daily was quite thick.

 

[duraleigh]

FT pool,

I can't find the "success" in your post. It sounds like you had a pool that you were managing just fine until someone talked you into phosphate remover.

The result was

I dealt with a cloudy pool and daily cartridge cleanings for a full week.

and, you still have phosphates!

Help me understand what was successful about that?

 

[FT Pool]

I consider dropping 2000 ppb a success.

Seems to me I maxed out the volume of phosphates that a single dose of Phosfree can bind with. Most people look to get down a few hundred ppb or like the OP’s pool a high level at 2000ppb. My pool was almost 5000 ppb which is an extremely high level to reduce.

 

[Donldson]

I consider dropping 2000 ppb a success.

Why? You said yourself that you were successfully running your pool before and then decided to give in to the phosphate propaganda and then dealt with a cloudy pool and constant filter cleanings for a week. And you still have high phosphates (according to whatever source is convincing you that this is a problem).

So other than a number on a pool store test sheet, what has tangibly improved with your water?

 

[FT Pool]

I completely agree with the quote in the OP's post:

"I fully understand that phosphate removal does not prevent algae. It's just removing a food source. At best, it makes it a bit harder for a bloom to start if your FC/CYA levels drop too low."

and get that phosphate removal is unnecessary as long as you are maintaining your sanitizer. I (like the OP) wanted them out and was wiling to go through the process to do it. I've scraped the bottom of the ideal range of chlorine and gotten a minor algae bloom. I (like the OP) just want to remove any additional food source.

 

[Donldson]

Right. Except you still haven't fixed the problem that the pool store is telling you that you have. Which means you are already committed to buying more PhosFree.

On that topic, why do pool stores like talking up phosphate removal so much that you are fully sold despite the troubles it has caused you? Oh yes, PhosFree. Such a great product... for them. See, Natural Chemistry makes PhosFree. Takes about 68 ounces to remove 1200 ppb. Did you know Natural Chemistry also makes another phosphate removal product? Yes, their Pro Series. You won't find that on store shelves. Do you know how much of that it takes to remove 1200 ppb of phosphates? 2.5 ounces. Here's the kicker: wholesale these products are sold at the same price...

The pool store, honest fellas they are, is selling you a product that has been watered down to 3.6% strength. Now, what possible motive could there be for them to convince you that phosphate removal will fix a problem you can't really see and then sell you a product that is marked up 30x compared to the stuff they would be selling professionals?

 

[FT Pool]

I get pool stores are there to make money and sell you stuff. Stuff you don't need.

My own test yielded the phosphate results. Not the pool store. I went to the pool store to ask what they had on the shelf to correct it. It was all of $30 if I recall so not exactly going to break the bank.

Donldson - If you have a link or source to buy pro strength phosphate remover and I only need 5 ounces it would be appreciated if you could post it or PM me. I will put it in and share my results.

 

[Dan Morrill]

This was not meant to turn into a thread debating the motives of pool stores. I know I can maintain a clear, clean pool with way more phosphates than I currently have.

No pool store is pushing this on me. This is completely my own idea that I am contemplating and wanted to connect with people who have tried it.

My motivation is to make my pool a little less hospitable in case I accidentally drop below minimum FC/CYA. If it does drop, and the removal of the phosphates prevents a full out bloom, the cost of the removal would likely be less than the excess chlorine cost of an extended SLAM and excess reagent cost of testing at SLAM levels (which are prohibitively expensive here in Canada).

 

[duraleigh]

While you are lowering your phosphates, you must also consider lowering nitrates which are likewise algae food, too.

I am not positive which algae likes which best (nitrates or phosphates) but they both serve the purpose of food and, following the logic, wouldn't you need to get rid of nitrates, too?

Nutrients such as nitrogen (N), phosphorus (P), and potassium (K) serve as fertilizer for algae, and are generally necessary for growth.

Uh-oh looks we have to go buy some potassium remover, too. Sorry, I am not buying in.

 

[Leebo]

The use of phosphate removers has been discussed multiple times and I suspect we'll see the discussion multiple times in the future. In my eyes, there really are two correct answers. If a user lowers their phosphate levels the risk of getting algae is reduced IF they allow their FC drop below minimum. That said, IF a user maintains their FC.........they likely won't get algae anyways. We can go round and round in circles over the pro's and con's and they're all right...........but let's also point out a few items to follow IF a user does wish to stress about their phosphate levels. I've removed phosphates from my pool about 4 years ago and below is some of the stuff I've learned along the way.

1. Please don't use the rubbish from the pool stores. The stuff is so watered down it's a joke, and often contains a clairifier that could mess with your filter. Use a quality product like Orenda 10,000 or Seaklear. While the prices are slightly more expensive, it'll reduce your level a fair amount more than the rubbish from the store.
2. If you have high levels of phosphates, please expect cloudy water. This is occurring because the phosphates are being removed from the water and needs to be filtered out. I say this as it's smart to do phosphate removal early in the year or when the pool won't be in use. Don't add phosphate removers just before your huge 4th of July party and then cry because the water is cloudy.
3. Use your own test kit. A good kit costs like $20.........call me crazy but for that amount I'd just personally rather avoid the stores......plus the results can be trusted.
4. Don't bother using phosphate removers if you have green water. First you're unable to test as algae does alter your readings, so you'll likely waste some product and overdose. Second, algae contains phosphates, so as you kill the algae the phosphates WILL be reintroduced into the water........so you're just going to run in circles. Instead SLAM the pool THEN worry about removing phosphates.
5. Don't assume a low level of phosphates will 100% prevent algae. Continue to follow the FC/CYA Levels. Use phosphate removers ONLY as insurance in case you mess up.
6. Algae needs BOTH phosphates and Nitrates to survive.....not either or. Since there's not really any "nitrate" removers on the market, ignore these levels.

 

[duraleigh]

6. Algae needs BOTH phosphates and Nitrates to survive.....not either or.

I can find plenty of articles that suggest algae CAN grow on phosphates and can grow on nitrates but I can't find anything (yet) to suggest both nutrients are required. I don't want to hijack the thread so I'll go back to my original query.....

I can't find the "success" in your post. It sounds like you had a pool that you were managing just fine until someone talked you into phosphate remover.

I will add that a tenant from the beginning of TFP is not to add ANYTHING to your pool that you don't need.

 

[JJ_Tex]

I have a stupid, yet related question... how does one get phosphates in their pool in the first place?

 

[duraleigh]

Naturally occurring as are nitrates.

 

[ajw22]

I have a stupid, yet related question... how does one get phosphates in their pool in the first place?

Water runoff from fertilizer.

 

[CrystalRiver]

Also from fertilizer blowing or washing in.

 

[Leebo]

I have a stupid, yet related question... how does one get phosphates in their pool in the first place?

While phosphates are found and added to pool water naturally, the bulk of the time it's added by humans. As many have stated one common issue is runoff/overspray from fertilizer however there are other instances too.
1. Many products such as metal sequestrants do contain phosphates and users will quickly find themselves with high phosphate levels if they continue to use them.
2. Many cities use phosphates in the city water supply to help form a thin coating on the walls of the water pipes. This is to help reduce the risk of eroding the pipes.

 

[duraleigh]

The articles always mention run-off but I can't see that related to swimming pools. The runoff occurs into ponds from fertilization......I doubt many of us get much runoff of fertilizer into our pools. You should get in touch with your landscaper if you do.

 

[Homebrewale]

I have a stupid, yet related question... how does one get phosphates in their pool in the first place?

Using a phosphate containing detergent on the pool deck while cleaning with a pressure washer. There is a lot of overspray while cleaning. That's how I got it in mine. Since then, I only use high pressure water or if a stubborn stain, bleach. No problem with getting bleach in the pool.

 

[mas985]

I can find plenty of articles that suggest algae CAN grow on phosphates and can grow on nitrates but I can't find anything (yet) to suggest both nutrients are required. I don't want to hijack the thread so I'll go back to my original query..... I will add that a tenant from the beginning of TFP is not to add ANYTHING to your pool that you don't need.

Dave, it was covered in this post:

Phosphates.....are they worth removing??

Discussion is absolutely fine. Converting inconclusive discussions into TFP policy or advice dilutes our mission. We are a teaching forum dedicated to help everyday folks solve their everyday pool problems. Far too often, we have too much "parroting" on this forum wherein responders suggest...

www.troublefreepool.com

Also, there are several success stories in that thread including my own.

Phosphates.....are they worth removing??

So I'm volunteering two pools for the season, provided I can get experimental design help from mas985 or joyfulnoise. The strongest I can get is 200 g/L (~20%) 'rare earth salts' Phosphate remover (listed as 'lanthanum salt derivative' on the MSDS). Or I can get 15% that says simply 'lanthanum...

www.troublefreepool.com