Phosphate Removal

[cdchris1]

We are new pool owners this year, and after a few issues, I have finally got our water looking great. My test numbers are finally looking good (still working on TA, but much lower). After an acid cleaning of my salt cell and keeping my CSI slightly negative, my chlorine issues have gone away. During all of this, my PB noted that my phosphate levels are very high and they may not be able to warranty my SWG if I do not get them down. After all I have read here, I understand that phosphates probably did not contribute to my cell scaling (it was high CSI), and I really do not have to worry about them. But for warranty purposes, it looks like I might have to.

So, I bought some professional strength phosphate remover and have been dosing for the past couple of weeks (cleaning the filter in between). The test I bought only reads up to 1000ppb, so I really do not know how high they are (or were). I have gone to 4 different pool stores to see where my level actually is, but they all just reported them as +1000ppb as well. So I have been dosing at the 5000pbb directions hoping that would be enough. I plan on adding my 4th dose today. Could they really be that high? I'm just wondering if anyone else has experience with phosphate removal or any advice they could give. Thanks.

 

[gwegan]

What are the phosphates in your fill water?

 

[JoyfulNoise]

Use of metal and scale sequestrants will eventually show up as phosphates.

For the test you can dilute a sample 1:1 with distilled water to see if it will register then multiply results by 2. If you use a 1:3 dilution then you multiply by 4.

 

[JoyfulNoise]

Our TFP metal expert, swampwoman, had pool water with over 50,000 ppb (50ppm) PO4 in it.

 

[cdchris1]

My fill water tests at +1000ppb as well, but is not nearly as dark blue as my pool test.

I have been using Jack's Magneta Stuff (I used one bottle of Pink Stuff), to keep the iron sequestered. Our fill water was very high in iron. So if the sequestrants show up as phosphates, I am really just chasing my tail by adding the Magenta Stuff and then trying to get rid of my phosphates? Maybe I should just give up on the phosphates and hope for the best with the SWG warranty (if needed). Or should I be able to clear out my phosphates faster than I add them?

I will pick up some distilled water and try diluting to see if I can get a good value.

 

[JoyfulNoise]

Yup, you are fighting your own water sources. Jacks Magenta Stuff is an HEDP (phosphonate) based sequestrant that chlorine will breakdown over time into phosphates.

Your only option is to get water trucked in to refill your pool with that is phosphate free and then strictly control evaporation and refill. Very hard to do in your case with fill water that is > 1000ppb PO4.

 

[cdchris1]

Thanks for the information. It's funny, the Jack's website specifically says that the Magenta Stuff 'will not yield phosphates' (MAGENTA STUFF | Jacks Magic).

Is Jack's Pink Stuff any better? I was recommended the Magenta Stuff since we have a fiberglass pool (not sure why), but I think they would both control my iron problem. Is there any sequestrant that would be better? Or should I keep using the Magenta Stuff and just give up on the phosphates.

With it being fiberglass, I do not think a complete refill with trucked in water would be justifiable if I can manage everything else and just ignore the phosphates.

 

[JoyfulNoise]

My bad. The magenta stuff is PAA - polyacrylic acid. It will not yield phosphates on breakdown.

So it is ok to use.

 

[JoyfulNoise]

Most sequestrants for pools are limited to HEDP or PAA. So you're stuck with the Magenta Stuff for now.

 

[gwegan]

Another idea is to get an iron filter. there are several on amazon and you can make your own. Just search around on here and on You Tube. They do work and remove iron.

However even the best iron filter won't take out all the iron, but if you get the levels down it can cut down on sequestrant use.

No easy answers here.

 

[cdchris1]

Thanks for the tips. I will look into a filter for when I have to fill. I see a lot of posts mentioning the CuLator (although with varying results). That might be worth a try as well.

I know our fill water phosphates are high, and using Jack's Pink Stuff did not help, but are there any other sources of phosphates that I might be overlooking. We keep our pool covered most of the time, so I tend to rule out plant mater or fertilizers.

 

[JoyfulNoise]

Sources of phosphates are -

1. Municipal fill water supply using orthophosphates to control scale and corrosion;
2. HEDP-based metal sequestrants used by pool owner;
3. Environmental sources (leaves, dead critters, fertilizer, etc)

To give you a scale, I have no phosphates in my water supply, I use no sequestrants in my pool (no metals), my pool is uncovered (mostly) but gets minimal landscape debris and I do not live near any major commercial farms or fertilizer sources. My phosphate loading seems to be about +35ppb/month. So I would consider my pool to be on the low end of the phosphate loading scale.

 

[cdchris1]

It looks like I may have found another source of phosphates in my pool.

The Case of the Mysterious Pool Deposits - AQUA Magazine

My PB had recommend using Acid Magic instead of regular MA. I was sold and have (had) been using it every regularly to get my TA down. It was working great but after reading that it has phosphates, I'm done.

 

[Divin Dave]

I'm done.

Good for you!

 

[Swampwoman]

Our TFP metal expert, swampwoman, had pool water with over 50,000 ppb (50ppm) PO4 in it.

Hi Cdchris! I was out of town due to illness and ultimately, passing of a family member and am just now catching up but thought I'd chime in.

I ran an Aquarite t15 cell all season with the high po4 Joyful reports...it ran fine, but it did shed scale that I was able to test and confirm was phosphate scale. I now have new, trucked water due to a liner change.

Pentair, IMHO, are jerks about their warranty. Those of us on well/high iron are stuck between a rock and a hard place with their demand for such unreasonably low po4 levels. Frankly, if your source water is over 1,000 ppb, I don't think you'll be able to meet their low warranty level. Nor do I know if you'd NEED to for operational purposes...te aquarite is "self cleaning" in that it reverses polarity to she'd scale. If the Pentair operates the same way, you'd be fine.

Re jacks Magenta, just know that jack's own tech would tell you you'd still be better off with Purple for swg than the Magenta when it comes to success with iron sequestering. But if you can avoid staining with the Magnta you're golden.

With respect to phosphate removal, I'm just going to throw out a suggestion since you're dealing with a new pool : if your dilution still shows high po4 after the 4th dose of the remover you're currently using, you might want consider trying Alum floc instead because it removes both po4 AND iron...if it works at all Floc can be temperamental ph-wise in its formation.

Its cheaper for high volume removal (Leslie's alum, at about $26 for 8 lbs). You MUST be able to vacuum to waste though for this approach.

My filter is sand, which is ideal for additives/iron removal etc. I don't know anything about cartridge filters so I don't want to give you bad advice..,make sure to check for contraindications with your filter type...I know for example of one floc-type polyacrylate product that is for use ONLY with sand filter...so it might stand to reason that other products have this recc in the fine print.

How many ppm iron is your well?

In my case, I plumbed a dual softener to my pool fill spigot to reduce iron load, then reduce again with a 25:1 micron 10" filter in a big blue Pentak housing. Food for thought since you're early in the iron management scene

Let me know if you want more details or links to any of these things. Happy to share the crazy things I've tried

And if dilution doesn't work to read your po4, check out Hanna Instruments high limit po4 reader...it goes to 30,000 ppb (yes, still had to dilute.) Phosphate High Range Checker® HC - HI717 - Hanna Instruments

Pool stores have absolutely no clue, nor any method, to test po4 in well/iron/sequestrant pools, just so you know. The highest ive seen one read (a store associated with an actual PB) was 2500.

 

[rwood5093]

I can't comment on the phosphates, but I can comment on my experience with iron. We had amazing success with a 5 gallon bucket filter and the pool water is now cleaner than my drinking water. We used a hose end filter to top it off and had a little that was removed but the filter, but other than that you'd never know we had 2.1ppm iron in our fill water. Our FC was about slam level, which precipitated the iron, and the bucket and polyfill removed it in under 36 hours. It was amazing.

 

[cdchris1]

After my 4th dose, my phosphates were still +4000ppb (I gave up diluting any more). I decided to take a little break from the treatments for my own sanity. I did purchase a CuLator that is currently in my pump basket (the directions say not to use while using a phosphate remover anyways). So I am giving that a try for my iron. I read about the bucket method, and was a little skeptical (thanks rwood5093 for verifying its effectiveness). I will have to give some though on rigging that up pump wise (I will have to use a stand alone pump and just recirculate). That might also be something to try with my fill water (I also have a filter on order for the hose). Our fill water is about 1.5ppm, so it is not horrible, but still not good. I have been fortunate that with the auto cover we have minimal evaporation, mostly just splash out from the kids. I have been able to utilize just the rain to refill when needed and avoid the hose for now.

Thanks for all of the tips Swampwoman (and sorry for your loss). The Alum floc definitely sounds interesting. From what I have read so far though, it does not work well with cartridge filters, and I do not have the option of vacuuming to waste. Do you think my robot would be able to handle it? I also have a hand vac that I use in the spa that I could get the hard to reach areas. Are there any negatives from using the floc? I would like to get as much of this cleaned up in the next month or so before we have to close so I can open clean! The winter will give me some time to ponder your longer term solutions.

 

[Swampwoman]

Cdchris, in that case I'm afraid I'd suggest you avoid the floc...the robot would only stir it up and the hand bot likewise would just break the particles for reforming. You'd likely just end up with a goey mess.

1.5 ppm is pretty high for sequestering purposes alone, so any secondary filtering to can work up will improve your maintenance going forward.

Two things come to mind...in pool, you could see if The Slime Bag | The Easiest Way To Maintain Crystal Clear Pool Water. with a return attachment helps reduce load. On fill, this is my preferred set up as the filter is disposable (sold separately) Pentek 150237 #10 Big Blue Filter Housing, 1 Scientific

 

[duraleigh]

my PB noted that my phosphate levels are very high and they may not be able to warranty my SWG if I do not get them down.

Sorry to be late to the dance (and haven't yet read the whole thread) but I would like to pursue this.......just exactly who won't warrant what and can they offer a common sense reason?

 

[cdchris1]

Swampwoman - What cartridge filter do you use with that housing? I was ordering this one (Amazon.com: Camco 40631 EVO Premium Water Filter: Camco: Automotive) that includes a 5 micron cartridge. The slime bags are interesting (filtering down to 1 micron?). I will have to do some more research on those.

Speaking of micron filtering, does anyone know what it is on the Pentair cartridge filters? I have not been able to find it yet.

duraleigh - The quick story on the warranty is that my PB told me that Pentair may not warranty my SWG if I have problems due to my high phosphate levels. He had another owner that had phosphate scaling that damaged the cell and Pentair did not warranty it. Someone else started another thread about this as well (Apparently Phosphates Do Matter...).