It seems it may be possible to greatly reduce iron in pool water. I look forward to Chemgeek's opinions.
This is of course is extremely:
: relating to a scientific experiment or to scientific experiments in general
: made or done in order to see how well something works
: using a new way of doing or thinking about something
So please wait for Chemgeek's remarks, before making any commitment.
Note this was done in a plaster pool using liquid chlorine/bleach, and may not work in an any other type of setup.
Using the AA process for iron stain removal is good but it does not solve the problem of it returning. Some of Einstein's quotes, which I keep at my desk to control myself, seem as if they might be helpful here in moving the solution along:
Everything should be made as simple as possible, but not simpler
Anyone who has never made a mistake has never tried anything new
Common sense is the collection of prejudices acquired by age eighteen
The only thing that interferes with my learning is my education
The whole of science is nothing more than a refinement of everyday thinking
The important thing is not to stop questioning. Curiosity has its own reason for existing
Whoever undertakes to set himself up as a judge of Truth and Knowledge is shipwrecked by the laughter of the gods
Insanity: doing the same thing over and over again and expecting different results.
Not everything that can be counted counts, and not everything that counts can be counted
Knowledge isn't truth. It's just mindless agreement. You agree with me, I agree with someone else - we all have knowledge. We haven't come any closer to the truth. You can never understand anything by agreeing, by making definitions. Only by turning over the possibilities. That's called thinking. If I say "I know", I stop thinking. As long as I keep thinking, I come to understand. That way, I might approach some truth
If you are out to describe the truth, leave elegance to the tailor.
On being reproached that his formula of gravitation was longer and more cumbersome than Newton's.
Everyone sits in the prison of his own ideas; he must burst it open, and that in his youth, and so try to test his ideas on reality
It's not that I'm smart, it's just that I stay with problems longer
And from a very successful German businessperson
Other people have smart children to
By pure accident I ran across this idea after I discovered a jug of "PHOSfree Commercial Strength", manufactured by "Natural Chemistry" in my garage storage. I have used it before for orthophosphate removal, but as orthophosphates are not a major issue according to this forum, I forgot about it. As I had a jug I thought I might as well use it, the clouding effect was not an issue in the past, it cleared up in about 24, sometimes 48 hours, and filter blockage was not too bad. To be extra careful before I used it I "Googled" the MSDS, see here:
It states that the main ingredient is "Basic aluminum chloride" with Acid, known commonly as a PAC (PolyAluminum Chloride). I then "Googled" "aluminum chloride waste water management" and "aluminum chloride boiler treatment". It was very interesting to note that it now used in preference to Alum for removal of not only orthophosphates, but also heavy metals (iron being one of them), and silica. Many other items are also removed among them organic contaminants, nitrates, and others. It seems it is used heavily in the production of high grade Muriatic Acid to remove contaminants, mainly heavy metals.
Silica in the water supply on Oahu, not the other islands as their water is primarily from streams and rivers, is about 50 ppm in the municipal tap water, obviously a major staining issue. Our water comes from ancient volcanic aquifers under the surface of Oahu. These high ppm are also true for other parts of the US notably, California's Central Valley area around 60 ppm, and many areas of Texas where the ppm range from 38 ppm, to as high as 100 ppm in a few area. I got rid of my silica staining on the walls using the Hydrogen Peroxide method in conjunction with an Ascorbic Acid (AA) treatment of 1 lb, but I needed 4 times as much HP as I mentioned in my previous post on the subject, there was literally a little beach of sand both light colored and orange colored sand/crystals at the bottom of the pool after draining.
The interesting thing here is that my own experimentation experience deviated greatly from the amount that boiler cleaning papers mention for removing both calcium carbonate and silica scaling. This is most likely due to the fact that they do it on a regular basis, so there is less to remove, and I did it for the first time in 16+ years, thereby requiring 4 times as much Hydrogen Peroxide to do the same job, although the Ascorbic Acid required was the same being only one pound for 10,000 gallons.
Silica in most US areas averages around 8ppm to 16 ppm, not a real staining concern for the first 6 to 10 years. Often on this forum I will read that the Vitamin C tablet did not work, my guess in the absence of iron staining that it is silicate scale which is much harder to remove, and typically cannot be removed with the low pH treatment, although a really aggressive and damaging acid wash might accomplish, this but at what cost to the integrity of the plaster.
The recommended method, it seems, in cold water such as pool water, is first to remove the phosphate at a pH between 7.0 and 7.6. Then to do one or two additional treatments to remove silica and heavy metals (iron, etc.)from the water (not the surfaces), at a pH of 6.8 or below. My second and third treatments were done at a pH of 6.7. And yes I have a properly two point calibrated pH meter (recommended). Using half the jug, for the phosphate removal at a pH of 7.4 (note it seems it cannot remove the last 100 ppb according to the literature I read), then two additional treatments using a quarter of a jug at a pH of 6.7, using Muriatic acid to lower the pH, starting at an alkalinity of around 80 -90 it reduced it to around 50 ppm.
It was further recommended reading the "Googled" scientific papers to add and use a Copolymer to enhance the effect of flocculation, I used Jack's Magic Magenta Stuff, MSDS here:
An "Acrylic Acid Copolymer"
After the first 2 treatment I added an additional 5 oz to my 10,000 gallon pool, after the final treatment I added the recommended higher initial recommended dosage. Ironically the cleaner the pool the high the dosage needed.
Well this was done about 3 months ago, and by keeping the pH at 7.5, and adding a weekly dose of the Magenta stuff (Acrylic Acid Copolymer), my iron problems have gone away. Occasionally I add a little more copolymer if we have had heavy winds (over 26 mph) as it seems to bind any iron deposits on the pool floor.
The papers I read on line stated to use phosphonic acid, such as HEDP (Jack's Magic Purple Stuff) in doses of a minimum of 5 ppm (Jack recommends 12 ppm) in conjunction with Acrylic Acid Copolymer to control iron staining but I can no longer buy the Purple Stuff in my area, the best pool person I know told me he only uses the "Magenta" and it works, perhaps this is why the stores are no longer carrying it. Personally I would prefer both HEDP and the copolymer, but I cannot get it.
1. As regards the copolymer "Jacks Magic Magenta Stuff", from what I have read it performs optimally at a pH of 7.5. For waters/pools with very high iron, other heavy metal content, silica, or organic debris, even going triple the dose is not dangerous, as I understand it
2. The Aluminum Chloride does seem to lock up the CyA (Cyanuric Acid) for about 2 - 3 days, by which I mean a 50 ppm level will show if measured a 30 ppm level, a drop of 20 ppm. And indeed the daily chlorine drop will be greater than usual. After 2 -3 days it will again go back up to 50 ppm, and because the pool is a lot cleaner, the chlorine usage may drop.
3. The level of cloudiness that you will incur initially seems to be dependent on both the phosphate level and organic debris in the pool, if you have a lot say 2,500 ppb of ortophosphates , and other organic debris in other words much higher TDS (Total Dissolve Solids) than your salt level would imply then it will be a lot milkier for 24 - 48 hours. If it takes longer do not worry. But measure your orthophosphates again to see if you did bring them down to around 100 ppm, if you did not add sufficient to get them into that ppm area, before doing the last 2 treatments.
Once you get down to 100 ppm the clouding is very little, the next treatment may take only 12 hours to clear. The final treatment maybe only 8.
4. Note of caution: Only Aluminum Chloride based phosphate remover should be removed, NOT "Lanthanum chloride" based removers, such as regular "PHOSfree".
5. If you are going to use a different PAC (PolyAluminum Chloride) from Jack's Magenta Stuff, make sure it can handle high chlorine, over 1 or 2 ppm in this case, as most cannot.
6. Lastly doing this is not inexpensive, but if it keeps lasting and gives piece of mind, and allows one to run at a relatively benign pH of 7.5, it seems to me to be cheap at the price.
Anyway 3 months with absolutely no iron issues is, I believe, a first for me, but am not sure as I getting rather old and my memory is not as good as it was.
It appears that by removing both carbonate and silicate staining with HP and AA from the pool surfaces it helped to avoid iron getting glued/trapped. But the Aluminum Chloride treatment removed iron and silica from the liquid water I believe, and the weekly copolymer treatment (Magenta Stuff) seems to control both iron and silica in the water quite well it seems.
I think this may be worth giving a try if you have heavy iron fill water, because refilling with more water obviously will not help.
Only those of us with long suffering relationships with iron and silica scaling can truly comprehend what a pain it is. Those of you without this ongoing experience/nightmare, or minor experience, this may seem over the top. I realize this. But for me to walk out to a pool where the pH stays at around 7.5 for days on end and have no stains is like Galileo Galilei, knowing that while most of the world thought him wrong, and tried by the Inquisition he knew that by a combination of theory, calculations done by others before him, and experienced observation, and experimentation he was on the right track. Unfortunately he lived out the remainder of his life under house arrest.
So while I will definitely take all comments and perhaps massage the methods, as I did with HP by quadrupling the quantity, based on swampwoman's comment and a personal unsuccessful experience , I will stick with it for now, unless someone comes up with a better method, or chemical(s). Hoping you who read this do not put me to under internet arrest.
Of course the very faint possibility, nay minute possibility, exists that I could be wrong in my assumptions. At which point I will drown myself in a barrel of Chateau Lafite Rothschild, Vintage 1961!
Here are a few assorted articles in no particular order (there are many more), and of course you should "Google" yourself: