Thanks again Matt. I'll let you all know what I do and what the results are. I won't end up being as quantitative as you because I haven't been keeping actual data, and my pool is crystal-clear now, but I'll try to post something useful.
Phosphates.....are they worth removing??
- Thread starter Leebo
- Start date
Mine is actually the high range one given the sequestrant use and high po4 conditions here. Phosphate High Range Checker® HC - HI717 - Hanna Instruments
The Hanna Meter also self-calibrates in that each time you test, you first read the sample without the reagents. So its calculating the delta
Even though it gets up to 30,000 ppb, its pretty sensitive at low levels and will cross-corroborate with the k1106, which i also own, consistently.
I would love it if someone created this kind of photometer for the cya test
Update on the Phos-Monster Pool and Experiment Drawing to Close
I am happy to announce an early abandonment of my 50,000 ppb po4 experiment in terms of SWG cell function, as I am scheduled for trucked water replacement Aug. 16 due to the installation of a new liner. My curiosity would have almost had me continue if I had have been able to store and then reuse my highly phosphonic water...but then I gave my head a good shake and said, Swampy, WTH
I have one more round of tests to try to figure out in the formation of my own personal guidelines on po4.
Though inconclusive in some ways and not terribly scientific in terms of lack of control, I can report the following empirical data of SWG use, scaling, and algae formation in extremely high phosphate levels last read in the 50,000 ppb range.
1. After 3.5 months of operation, my Aquarite T15 cell has operated flawlessly in terms of stable FC production with an apparent daily consumption in the 1.5 ppm range maintaining a constant 5-6 ppm FC with my cya at or near 70.
However, I now highly suspect that this successful chlorine production is in part credited to the reverse-polarity feature of the unit, which sheds scale, likely moreso with Jacks Purple, which has a proprietary cell cleaner in it. More on this in a bit.
2. Either because of the extremely high PO4 level or despite it, my pool water did not prove to be especially reactive to algae formation when stored in a white 5 gallon bucket in the sun for 28 days til it started to turn green, about a week after FC completely zeroed out.
3. I now believe, but may try to figure out a few final tests to verify, that Chem Geeks calculation on phosphate scaling is pretty accurate and a real phenom despite my continued production of FC. The observations that have led me to that tentative belief are as follows:
A) I began getting small amounts of blue-white flakes noticeable on steps early in production that I initially assumed was the jack's chelating whatever trace copper I had in the water. It looks like copper carbonate.
B) But then my 15 year old Hayward copper heat exchanger failed. It was 15 years old, so it would be hard to argue the salt exacerbated it this year, because I'd only added 2 bags of salt to get to swg OP level. So if it were salt, it would have gone anyway. BUT phosphate scale is in fact a real phenom in boiler mechanics, and when they were removing the unit, I could see drip lines of light turquoise copper carbonate but a more substantial buildup of white scale. My ch level has never been higher than 160 and currently is 100. But in chemgeek's formula, there is a relationship between calcium level, phosphate level and temperature, so one does not need a "lot" of calcium if one has very high, eg 30,000 ppb phosphate levels together with higher temperatures, I will dig up and repost his initial calculations on this later.
C) When the water was cooler for a week before my new heater came in, I didn't notice as much flaking.
D) Within 24 hours of installing the new, cupronickel heater, I began to again get heavy shedding. The installer and Jacks Magic tech both believe it could not possibly be the heater already.
E) I noticed a pattern of increased flake production when I boosted the swg before a party last week. I have preserved some flakes for testing.
F) MA added to flakes in shot glass did NOT fizz, as one would expect with much calcium carbonate. Instead, it turned yellow.
G) I suspect this is phosphate scaling. To determine its origin, I've ordered a dummy cell to swap out for a test before I drain next weekend. At that time I will also clean the cell and evaluate degree, if any, of scale in housing and on plate.
H) I will now see if I can find any home test to determine the actual composition of the flakes.
If my suspicion is correct...that high po4, high heat even with low ch generate this much scale in a well-controlled pool ph-wise, then I will proactively reduce po4 periodically in the future once I have a clean/manageable start to avoid this issue particularly in my new heater, but also in my cell.
Here's a picture of my shot glass/ma test, and a picture from an article about phosphate scaling.
I am happy to announce an early abandonment of my 50,000 ppb po4 experiment in terms of SWG cell function, as I am scheduled for trucked water replacement Aug. 16 due to the installation of a new liner. My curiosity would have almost had me continue if I had have been able to store and then reuse my highly phosphonic water...but then I gave my head a good shake and said, Swampy, WTH
I have one more round of tests to try to figure out in the formation of my own personal guidelines on po4.
Though inconclusive in some ways and not terribly scientific in terms of lack of control, I can report the following empirical data of SWG use, scaling, and algae formation in extremely high phosphate levels last read in the 50,000 ppb range.
1. After 3.5 months of operation, my Aquarite T15 cell has operated flawlessly in terms of stable FC production with an apparent daily consumption in the 1.5 ppm range maintaining a constant 5-6 ppm FC with my cya at or near 70.
However, I now highly suspect that this successful chlorine production is in part credited to the reverse-polarity feature of the unit, which sheds scale, likely moreso with Jacks Purple, which has a proprietary cell cleaner in it. More on this in a bit.
2. Either because of the extremely high PO4 level or despite it, my pool water did not prove to be especially reactive to algae formation when stored in a white 5 gallon bucket in the sun for 28 days til it started to turn green, about a week after FC completely zeroed out.
3. I now believe, but may try to figure out a few final tests to verify, that Chem Geeks calculation on phosphate scaling is pretty accurate and a real phenom despite my continued production of FC. The observations that have led me to that tentative belief are as follows:
A) I began getting small amounts of blue-white flakes noticeable on steps early in production that I initially assumed was the jack's chelating whatever trace copper I had in the water. It looks like copper carbonate.
B) But then my 15 year old Hayward copper heat exchanger failed. It was 15 years old, so it would be hard to argue the salt exacerbated it this year, because I'd only added 2 bags of salt to get to swg OP level. So if it were salt, it would have gone anyway. BUT phosphate scale is in fact a real phenom in boiler mechanics, and when they were removing the unit, I could see drip lines of light turquoise copper carbonate but a more substantial buildup of white scale. My ch level has never been higher than 160 and currently is 100. But in chemgeek's formula, there is a relationship between calcium level, phosphate level and temperature, so one does not need a "lot" of calcium if one has very high, eg 30,000 ppb phosphate levels together with higher temperatures, I will dig up and repost his initial calculations on this later.
C) When the water was cooler for a week before my new heater came in, I didn't notice as much flaking.
D) Within 24 hours of installing the new, cupronickel heater, I began to again get heavy shedding. The installer and Jacks Magic tech both believe it could not possibly be the heater already.
E) I noticed a pattern of increased flake production when I boosted the swg before a party last week. I have preserved some flakes for testing.
F) MA added to flakes in shot glass did NOT fizz, as one would expect with much calcium carbonate. Instead, it turned yellow.
G) I suspect this is phosphate scaling. To determine its origin, I've ordered a dummy cell to swap out for a test before I drain next weekend. At that time I will also clean the cell and evaluate degree, if any, of scale in housing and on plate.
H) I will now see if I can find any home test to determine the actual composition of the flakes.
If my suspicion is correct...that high po4, high heat even with low ch generate this much scale in a well-controlled pool ph-wise, then I will proactively reduce po4 periodically in the future once I have a clean/manageable start to avoid this issue particularly in my new heater, but also in my cell.
Here's a picture of my shot glass/ma test, and a picture from an article about phosphate scaling.
Saturn94
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Interesting. I've never seen flakes in my pool. I assume my phosphate is very high due to the regular diet of Jack's Purple Stuff I've been using for years. The Taylor phosphate test says its >1000ppb.....I haven't tried a dilution test to get the actual level.
My salt cell always looks clean when I close the pool for the winter.
Do you use borates? I understand borates can help protect the cell. I maintain 50ppm borates in my pool. Maybe that's the difference?
I do not have a heater.
My salt cell always looks clean when I close the pool for the winter.
Do you use borates? I understand borates can help protect the cell. I maintain 50ppm borates in my pool. Maybe that's the difference?
I do not have a heater.
I do use borates and keep them to 50 ppm. My hunch is that its just the combo of high heat (we heat to 88 degrees) and abnormally high phosphates, but I'm looking for ways to test the flakes to figure out composition and will update if I find anything
Saturn94
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Hmmmm.....it's not unusual for our pool to reach 88°-90° during peak season; still no flakes of any kind.
I hope you're able to ascertain the composition/source of the flakes.
I hope you're able to ascertain the composition/source of the flakes.
Haven't figured out a way to test yet.
In other news, since I have fresh water coming in, I read the treatment plant water test ... 1750 ppb po4...much lower than I am but if one believes the "500" ppb guidelines for swg cells, then anyone on treated water in West Michigan is already 3 times the limit on a freshwater fill
In other news, since I have fresh water coming in, I read the treatment plant water test ... 1750 ppb po4...much lower than I am but if one believes the "500" ppb guidelines for swg cells, then anyone on treated water in West Michigan is already 3 times the limit on a freshwater fill
- May 23, 2015
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In other news, since I have fresh water coming in, I read the treatment plant water test ... 1750 ppb po4...much lower than I am but if one believes the "500" ppb guidelines for swg cells, then anyone on treated water in West Michigan is already 3 times the limit on a freshwater fill
That is one of the reasons why some of the OG's on TFP disliked phosphate removers and using them. Why worry about removing them only when you're going to re-add them? Now granted this isn't for every water supply, but it just didn't make sense to get caught up in that cycle.
^one of the comments that struck me when I reached out to the author of articles on this topic was the question about what "real world" limits really are and how nobody knows that or knows how to begin to find out.
For example, one of the most popular pool tests for po4 goes to 1,000 ppb. In my city, someone on city water would find that useless.
In my case, since I don't drain at all in winter and since I will be topping up on well, which may require some sequestrant, I will likely do an annual removal to avoid the kind of buildup I believe caused the scale after years and years in old water.
Others with low po4 source water might find a maintenance routine useful in reducing consumption. But its clear the industry obsession is designed to cover chlorination flaws (eg users who don't maintain/test) and product flaws (over stabilization).
For example, one of the most popular pool tests for po4 goes to 1,000 ppb. In my city, someone on city water would find that useless.
In my case, since I don't drain at all in winter and since I will be topping up on well, which may require some sequestrant, I will likely do an annual removal to avoid the kind of buildup I believe caused the scale after years and years in old water.
Others with low po4 source water might find a maintenance routine useful in reducing consumption. But its clear the industry obsession is designed to cover chlorination flaws (eg users who don't maintain/test) and product flaws (over stabilization).
Thanks to a tip from OnBalance, I was able to test my scale by grinding it up with a mortar and pestle and suspending it in DI water just to check components (not levels). This scale for sure contains a LOT of phosphate, calcium, some iron and copper.
So, to recap, here is chem geek's original equation for phosphate scaling last year in my pool ...wherein the variables of calcium, ph, temp etc. all mean different levels. My hubby made a spreadsheet on this Calc so anyone who wants it can PM me I can confirm that in these conditions, phosphate WILL scale. My calcium was at 100, and I kept my csi on the negative side to theoretically avoid scaling, and in-pool water was controlled to 7.6. With that said, cell still running fine, perhaps due to the reverse polarity. You will see in the calcs though that at 25,000 ppb with only 75 ppm ch and ph at 8.5 inside cell, scaling is possible.
So, to recap, here is chem geek's original equation for phosphate scaling last year in my pool
...wherein the variables of calcium, ph, temp etc. all mean different levels. My hubby made a spreadsheet on this Calc so anyone who wants it can PM me I can confirm that in these conditions, phosphate WILL scale. My calcium was at 100, and I kept my csi on the negative side to theoretically avoid scaling, and in-pool water was controlled to 7.6. With that said, cell still running fine, perhaps due to the reverse polarity. You will see in the calcs though that at 25,000 ppb with only 75 ppm ch and ph at 8.5 inside cell, scaling is possible.
Saturn94
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Thanks for the report. It makes me wonder at what point would my pool experience phosphate scaling? Perhaps I'm getting enough rain dilution to keep it below the tipping point?
Hmmm.....now I'm really curious to see how much phosphate has built up in my pool. I'll have to dilute the pool sample. Any suggestions how much dilution to start with?
PS - I just remembered up until a few seasons ago I was dumping in a quart of phosphate remover at closing. Perhaps this was keeping it in check, and perhaps it wouldn't be a bad idea to go back to that practice.
Have you physically checked your cell since noticing the flakes?
Hmmm.....now I'm really curious to see how much phosphate has built up in my pool. I'll have to dilute the pool sample. Any suggestions how much dilution to start with?
PS - I just remembered up until a few seasons ago I was dumping in a quart of phosphate remover at closing. Perhaps this was keeping it in check, and perhaps it wouldn't be a bad idea to go back to that practice.
Have you physically checked your cell since noticing the flakes?
Hey Saturn, just dug up this thread now to report a test...sorry I didn't answer before...Yes, checked and cleaned scale...plates were clean but there were a lot of loose flakes. For dilution, try 10:1...bu if you have no issues I personally wouldn't bother
I'm updating this thread with a copy of a post I added to an older thread about rate of po4 build up after a water change...for posterity re: po4 mgmt. : this is te 2013 tread I found to be germane: What phosphate ppb will precipitate calcium phosphate?
I'm updating this thread with a copy of a post I added to an older thread about rate of po4 build up after a water change...for posterity re: po4 mgmt. : this is te 2013 tread I found to be germane: What phosphate ppb will precipitate calcium phosphate?
- May 23, 2015
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Sorry, I must ask for patience here. I have had a bunch of personal issues come up that has really hampered my efforts to focus on analyzing the data. It's been a really busy/rough Fall here ...
Short answer is I had very good results lowering my phosphates and FC usage but I need to really tally up my data from this year and the 2015 swim season to report a clear picture.
Stay tuned ...
Saturn94
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I still haven't noticed any scaling on the cell, loose flakes, unusual/elevated FC consumption, or SWCG performance issues, so I didn't add any phosphate remover at closing (I closed 2nd weekend in October). Also, I got lazy and never did a dilution test to get my actual phosphate level (it's >1000 according to the Taylor test).
I'll have to check my records to see if I recorded the last time I used the phosphate remover at closing. Perhaps we get enough rain dilution over the season to keep it below scaling levels?
Edit: It appears the last time I ordered a "closing kit" that included a bottle of phosphate remover was in Sept 2012. I still have a bottle of remover in the closet, presumably from that kit because I haven't bought any separately, so I'd say the last time I added remover was in Oct 2011.
I'll have to check my records to see if I recorded the last time I used the phosphate remover at closing. Perhaps we get enough rain dilution over the season to keep it below scaling levels?
Edit: It appears the last time I ordered a "closing kit" that included a bottle of phosphate remover was in Sept 2012. I still have a bottle of remover in the closet, presumably from that kit because I haven't bought any separately, so I'd say the last time I added remover was in Oct 2011.
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And the next time may be after a bout of amnesia, before you have re-discovered TFP
Looking forward to your conclusions, Matt, and ever impressed with your open-mindedness and testing with integrity. Hoping all is well for you and/or getting better.
Looking forward to your conclusions, Matt, and ever impressed with your open-mindedness and testing with integrity. Hoping all is well for you and/or getting better.
STARLOG Update 2017:
I've been remiss in reporting this summer, but here's a quick summary:
1. After fresh water change, I did not treat during winter in dome for phosphates due to floccing tendency in high concentrations and inability to use vac to waste in dome conditions.
2. pO4 level is now 25,000 ppb despite a full water change last year and a much "lighter" diet of sequestrant and keeping calcium in the 200 range, which using soft water, has meant adding. So any theories about age of water, swamp recovery, etc. are in fact ruled out now...this reading is from a year of sequestrant use on water that started out at 1,700 ppb po4.
3. My swg cell on annual inspection and cleaning showed no scaling. It is designed to she'd scale, and it does.
4. My swg output indicates it is fully capable of generating its rated 1.45 lbs of chlorine as in 24 hrs.
5. My heater is operating perfectly, though I still get the turquoise scale. Testing this year shows the ratio of scale component to be roughly 10 parts po4 to 3 parts copper to 2.5 parts iron.
6. I've hired a Raypak tech to come out mid-Sept to inspect and clean the cupronickel exchanger and plan to take pics. One part curiosity and one part possible preventative maintenance to ensure no operational failure during winter.
7. I have both alum floc and a gallon of commercial Seaklear lanathum chloride on hand. I've not decided about treatment plan yet before the dome goes up. I may not bother, as I may find that so-doing just removes my sequestrant.
8. It goes without saying for those few hardy souls who've followed this thread, but for posterity, despite the crazy po4 level as tested by Hanna hi range meter, I've never once had even an inkling of algae, or even cloudiness suggesting nascent algae forming. So I think we can safely put to bed any notion that po4 mgmt is required for any reason outside of a desired to run the lowest FC possible experimentally, and possibly that po4 mgmt is near futile for folks on well water who don't want stains.
Even if the exchanger is full of scale and its lifespan reduced, I'm not sure there's an alternative option in my case that would meet my objectives, short of periodic inspection and cleaning of heat exchanger.
I've been remiss in reporting this summer, but here's a quick summary:
1. After fresh water change, I did not treat during winter in dome for phosphates due to floccing tendency in high concentrations and inability to use vac to waste in dome conditions.
2. pO4 level is now 25,000 ppb despite a full water change last year and a much "lighter" diet of sequestrant and keeping calcium in the 200 range, which using soft water, has meant adding. So any theories about age of water, swamp recovery, etc. are in fact ruled out now...this reading is from a year of sequestrant use on water that started out at 1,700 ppb po4.
3. My swg cell on annual inspection and cleaning showed no scaling. It is designed to she'd scale, and it does.
4. My swg output indicates it is fully capable of generating its rated 1.45 lbs of chlorine as in 24 hrs.
5. My heater is operating perfectly, though I still get the turquoise scale. Testing this year shows the ratio of scale component to be roughly 10 parts po4 to 3 parts copper to 2.5 parts iron.
6. I've hired a Raypak tech to come out mid-Sept to inspect and clean the cupronickel exchanger and plan to take pics. One part curiosity and one part possible preventative maintenance to ensure no operational failure during winter.
7. I have both alum floc and a gallon of commercial Seaklear lanathum chloride on hand. I've not decided about treatment plan yet before the dome goes up. I may not bother, as I may find that so-doing just removes my sequestrant.
8. It goes without saying for those few hardy souls who've followed this thread, but for posterity, despite the crazy po4 level as tested by Hanna hi range meter, I've never once had even an inkling of algae, or even cloudiness suggesting nascent algae forming. So I think we can safely put to bed any notion that po4 mgmt is required for any reason outside of a desired to run the lowest FC possible experimentally, and possibly that po4 mgmt is near futile for folks on well water who don't want stains.
Even if the exchanger is full of scale and its lifespan reduced, I'm not sure there's an alternative option in my case that would meet my objectives, short of periodic inspection and cleaning of heat exchanger.