Used Hydrogen Peroxide for Removing Metal Stains - Results

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

Made a few additions and corrections to the above "The Hydrogen Peroxide and Ascorbic Acid Method - Operational Guide"


Here they are:


Interesting links on YouTube as to how it works:

http://www.youtube.com/watch?v=qT3mJrmhJHU

http://www.youtube.com/watch?v=iWpfHkWr5DY

and more technical:

http://www.youtube.com/watch?v=zQ3hHTvjgtc


A number of technical papers have noted that HP works better if salt is present. It might be a good idea to add salt even if you do not have a SWG (Salt Water Generator), to increase the effectiveness of this process. The maximum level of salt I would add would be 1200 ppm.

Copper is a pour catalyst in this procedure, unless the pH is in the range 8.5 to 10.0 so it might not help that much with copper staining (very few pools have copper staining issues), or it might take a lot of treatments if the pH is below 8.6. When I have time I will add a section on copper.

If using AA in the process, just before you add the AA, it is a good idea to bypass the heater, particularly if it contains copper, as the AA lowers the pH making it more acidic. Also if using AA remove your cleaner, at the same time, as this to can be damaged by the lower pH. Then open your main drain to allow for maximum flow to the filter.


More Hydrogen Peroxide will not make it more effective so do not waste your money
(But as nothing is certain, it is possible that more will help. Although one article I read stated that if the HP and AA (actually it was another acid) were not completely successful it could be due to the HP being used up by Iron Bacteria first. If then your AA treatment alone was not too successful adding somewhat more HP may help)

9. Three (3) hours after sunrise if you do not have a suction side cleaner,vacuum the pool surfaces, then backwash your filter, then vacuum again and backwash it again in the evening.

Another "Canary in The Coal Mine" is your white skimmer basket, or your white plastic thermometer, these tend to turn brown before metal stains seem to occur on the pool surface.

 

[Swampwoman]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

Sad to report that a week later without jacks and with ph no higher than 7.4 I have iron precipitate again on steps...poured jacket onto it and it disappeared.

This means that the chelated iron test does not accurately measure sequestered iron, or that my heater introduced trace amounts of iron. It only happened after raising pool temp and the adding a large (gallon 10% for 5 ppm) amount of chlorine after heavy use on Saturday.

So I won't be kicking the jacks habit any time soon

 

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

Swampwoman,

I am sorry to read that iron came out of solution at a pH of 7.4. My own experience at 7.5, and a little higher, was that no iron came out of solution. It could be for one of the following reasons.

1. That you may not have a sequestrant test kit, from either Jack's or Palintest, to test to ensure you had sufficient sequestrant levels in the pool. Jack's recommends a minimum of 10 ppm, or up to 40 ppm for a pool with serious iron issues. I keep mine at 40 ppm. You will need to test twice a day during these treatments. This will keep any iron in solution up to a pH of 7.4, although I normally keep my pool at 7.3, but it does rise to 7.5, if I am too busy to check it, but still with no issues that I can see.

2. The following treatment is important if you want to rid the pool of iron and not just keep it sequestered. Unfortunately they were not in my first set of instructions. You may not have removed the iron once you sequestered it with AA and HP . This initial AA and HP treatment I believe helps sequester (put into solution) both iron stains and iron scale, the HP helps with the scale, if enough AA is used, but it will not remove the physical iron.

The way to do this as described in the new revised instructions is to let the pool rise to a pH 7.3, and then do the HP treatment again without the AA. Only when the pH is slightly alkaline will it then turn most of the iron into rust large enough to be caught by an HEDP sequestrant, such as Jack's Magic Pink or Purple Stuff, and taken out to the filter which you should backwash once the pressure builds up, once, twice and possibly more in your case. But you will need sufficient sequestrant in ppm in the pool to send it to the filter for backwashing. This should remove most if not near all the iron, unless your load is very high. A high iron load might be indicated by yellowish water; then you may need to do more HP treatments only (without the AA), re-checking the sequestrant level.

I did find a test kit on the internet that will measure total iron (Fe+2 / Fe+3). However I am not sure if the sequestrant might interfere with the readings, also it only measures zero, and 0.30, and up. Staining can occur at 0.2. I will post a question to chemgeek to see if it has any use in our cases. I have not used it but here is the link:

http://www.sensafe.com/product.php?recordID=481623-V

3. It was also mentioned that salt helps the process, though I am not sure if this helps to remove scale, iron, or both; the papers on it are unclear as to its overall effect. But adding around 1,100 ppm of salt to your pool, which I think is freshwater, may or may not help, but it seems from the papers that it will. I did not add this comment till after you had done your treatment. I added it after re-reading some papers. This as well may be the reason for your results.

4. When HP is added to the treatment, the best temperature to do these treatments are below 70F, and not above 77F, according to the research papers. What temperature was yours done at? These temperatures were, I believe/hope, mentioned in both the original and revised instructions.

4. I did over 5 treatments and this might have greatly enhanced my results over yours, and as mentioned it seems to me it works well in a saltwater pool.

Regarding the pool heater, if you have a number of solar panels, or the stains in a normal gas or electric heater have been with you a long time, it is possible that this could have created an environment for re-staining. In the original instructions for the AA treatment on this site it is recommended to bypass the heater so as not to damage the coils/pipes if they are copper, mine are titanium, and although I do bypass my electric heat pump heater, I do not get any re-staining. If the heater has many copper coils in the solar panel(s) re-staining might occur, but I doubt it, as the amount of iron in them should be quite low.

I hope these comments might show where the problem, you had, might be found. I realize that this is not an inexpensive treatment, nor are the methods an easy way of getting rid of these problems (iron and scale), but in my case it did work, or at least it seems so. Best of all it removed scale, one of the primary reasons iron staining re-occurs so quickly, and it seems the physical iron itself is gone as well, even at a pH of 7.5 or slightly above I have no re-staining.

If you have not already done it I would recommend doing an HP treatment only at a pH of 7.3, with salt in the water to remove the iron. Inexpensive salt (Diamond Crystal 40 lbs Salt Pellets for $4.49) can be found at Lowes, see this link:

http://www.lowes.com/pd_25654-113-7...&pl=1&currentURL=?Ntt=diamond+salt&facetInfo=

You will need 92 lbs to go from zero ppm to 1,100 ppm, for each 10,000 gallons.

Once again thank you for posting your results. Your reply comments are most welcome, as they might help us all to better understand the issues and help others.

 

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

Swampwoman,

A few additional comments.

If you did get rid of scale, and as I mentioned it might take more than one AA and HP treatment, and if you do remove most of the sequestered iron by doing the HP only treatment at a pH of 7.3, I think you will the find that Jack's HEDP sequestrant, so long as the pH is kept around 7.3, will keep the pool relatively stain free for quite a long time.

The fact that you added Jack's HEDP sequestrant and the re-staining went away at the steps I think is a good sign. It indicates that you probably removed any scale you had, otherwise the stain might not have lifted so easily. Now you just need to get rid of the iron. In my own pool the steps always had the worst scaling issues so it really does seem you dealt with the scale, if you had any before, maybe you did not. The initial HP and AA sequestrant treatment primarily seems to deal with scale and phosphates, but as mentioned if you had salt in the pool the percentage removal of phosphates, or iron, or scale might have been greater. Do you believe you had scale issues and if so did they go away?

If you see your that your white skimmer is getting iron stains again you may want to do just the HP treatment alone to remove excess iron, it will also remove light stains. The reason this might happen is that your sequestrant may get overloaded with iron, I am guessing that there is a breakpoint were it cannot hold anymore iron, despite having say 40 ppm, or whatever you decide.

I think that the dream of a completely non-staining pool, especially if the iron is brought by wind, is not really feasible, but can be better managed with HP and enough sequestrant. Fill water issues, if you have a filter, should be more easily managed with enough sequestrant. It is my understanding that the best iron filtration methods utilize HP.

Keeping your CSI in and around the -0.10 range, keeping an eye on your alkalinity and Calcium will also help, low alkalinity may cause scale and as a result staining will be more likely. But if you do not have a dog that drinks from the pool it is best to use Borax at 50 ppm to control pH bounce, as chemgeek stated, or you might be adding acid constantly to keep the pH down. Keeping scale out of the pool allows the sequestrant to more easily do its job, including possibly the removal of light stains and possibly light scale.

But if it were me I would always use an HEDP sequestrant, and a sequestrant test kit is a must.

Good luck.

 

[chem geek]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

I'm confused because I don't think that iron bound to sequestrant is going to get caught into the filter. The metal sequestrants bind better to the ferrous form of iron which is part of the reason you use a reducing agent first, but they also do bind to the ferric form just not as strongly (so have less capacity for it). What gets caught in the filter, I believe, is the ferric form of iron as iron oxide-hydroxide precipitate (i.e. rust) since it is rather insoluble, but mostly it's iron phosphate when lots of phosphates are present. As with any iron problem in a pool, the trick is to get the iron to precipitate in a way that it gets carried to the filter and doesn't re-stain.

The only thing I see in the AA and HP process that is helpful to getting rust to form without staining is that the hydrogen peroxide may oxidize the ferrous to ferric AND provide oxygen for rust at the same time because it produces hydroxyl ions when it gets reduced:

H₂O₂ + 2e^- ---> 2OH- ..... E₀ = +0.88V (at pH 7.5 it's higher, probably around +1.3V)

On the other hand, chlorine does something similar, though not as strongly (hypochlorous acid produces one hydroxyl ion though hypochlorite ion would produce two).

Also, don't forget that a lot of the precipitation of the iron was with phosphate so if the phosphate levels aren't high then you are more likely to stain than to form iron phosphate that gets to the filter. For whatever reason, the iron oxide-hydroxide (rust) tends to want to stain while the iron phosphate does not.

So maybe this is just as simple as not having as much phosphate in the water relative to what is needed for the amount of iron at the time of the treatment.

 

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

chem geek,

Yes, you are correct, the iron bound to the sequestrant is oxidized out turning it into rust which is then filtered out (but not as you correctly wrote by the sequestrant, my description of what actually occurs was incorrect) into large enough particles to be caught by the sand filter and then backwashed out. It seems, as many of the research articles wrote, that if one allows the pH to be slightly alkali, in my case I used 7.3, the HP oxidizes the sequestered iron to rust more easily. The reason I choose a pH of 7.3 is that I did not want it to re-stain, which may have occurred at 7.4. I will need to correct its effect in my instructions although the end result is, I think, the same, that being rust to the filter.


A WARNING NOTE TO THE CASUAL READER: One must first do the HP treatment with the AA treatment first before moving onto the HP only treatment.


As regards phosphate levels I believe that keeping the HEDP sequestrant, which is a Phosphonate based sequestrant, at 40 to 50 ppm allows enough phosphate in the pool to permit the process and success of oxidization.

Wikipedia mentions that;

"Phosphonates are effective chelating agents that bind tightly to di- and trivalent metal ions, preventing them from forming insoluble precipitates (scale) and suppressing their catalytic properties", and

"serve as "peroxide bleach stabilizers," by chelating metals that could inactivate the peroxide." It seems, at these ppms of 40 to 50, they also serve well as scale inhibitors and corrosion inhibitors.

I think the reason that it works better than chlorine is as you mentioned it has a greater oxidizing potential. However with enough HEDP sequestrant, 40 to 50 ppm, in the pool it might also enhance the "peroxide bleach stabilizers" effect, with chlorine as well, an added benefit during the regular day to day operation.

Having the amount of HEDP sequestrant in the pool at around 40 ppm, as measured by the test kit, seems to keep any residual sequestererd iron from re-depositing even when the pH floats slightly above 7.5. But this might also be due to the fact that most if not all the scale has now been removed, therefore it does not get to stick to the surfaces.

One last interesting net effect of doing this process:

I have a "Pool Pilot" SC-60 SWG cell, which I keep on power level 2, normally I run it at around 60%, in the summer for 5 hours in my 10,000 gallon pool, this gives a Free Chlorine reading of around 4 to 5 depending on the weather, heavy clouds or bright sunshine.

I now run it at 36%, and the FC measures around 7 to 8. I will lower the percentage again to see what will give me a FC of around 4 to 5.

I think the HP when it got rid of the iron also got rid of Iron Bacteria, and perhaps other unknown bacteria or "nasties", this then put less demand on the chlorine, or it might also be due to the higher level of HEDP sequestrant. I used to keep it at around 10 ppm last year, moving it up to 20 a few months ago, and now at 40 ppm.

Might you have any opinion as to why this benefit occurred?

As always thank you for your helpful clarification and correction, they are much appreciated.

 

[chem geek]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

If anything having a higher concentration of HEDP should increase chlorine demand because chlorine slowly breaks it down. So I don't have an explanation for your lower chlorine demand.

 

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

chem geek,

A few questions regarding this ongoing experimental procedure but firstly I will cover what I think is going on with the lower demand for chlorine.

I "Googled" with the following search "HEDP Sanitizer" and discovered that " most stock commercial preparations usually contain a synthetic stabilizer such as HEDP (1-hydro- xyethylidene-1, 1-diphosphonic acid) or dipicolinic acid (2,6-pyridinedicarboxylic acid) to slow the rate of oxidation or decomposition, so that the PAA you buy still has potency when you go to use it."

The link is here, with the above quote:

http://www.organicprocessing.com/opmayjune11/opmj11processing.htm

So it might be that the chlorine by having the sequestrant at about 40 ppm is slowing the chlorine's breakdown. Does this seem a reasonable explanation to you?

Also while I "Googled" I found my own post, from March, where I noted the same lower demand for chlorine, here:

http://www.troublefreepool.com/toxicity-of-hedp-t56605.html

And just for interests sake I found this link:

http://pmep.cce.cornell.edu/profiles/miscpesticides/misc_E_N/hedp/hedp_pet_0899.html

The questions that arise from the fact that oxidation or decomposition is slowed are:

1. Is this good thing or not, that oxidation or decomposition is slowed, in the day to day operation of the pool if one uses 40 ppm of HEDP? Jack's recommends this level for pools with more serious iron issues.

2. When doing the HP process, both with and without AA in the process, is it better to have 40 ppm, or 20 ppm, or 34 ppm (see below) as oxidation or decomposition is slowed? I think that having higher oxidation when trying to remove scale might be better but "Wikipedia" and other sites mention that a "dosage of 1–10 mg/L is preferred as scale inhibitor, 10–50 mg/L as corrosion inhibitor".

Wikipedia, is one of a number of sites that mention those numbers, link is here:

http://en.wikipedia.org/wiki/Etidronic_acid

Or is it a balancing act? The paper I linked to earlier in these posts, that discussed an in-depth study of scale removal, mentioned 34 ppm as the optimum ppm used for scale removal.

Even if the answer is that a lower ppm might be good, I did think of two possible benefits in having lower chlorine decomposition. A lower usage of the saltwater cell therefore a longer life, and pools with an undersized SWG might be able to produce higher "Free Chlorine" numbers.

3. Would lower decomposition and/or oxidation affect the pH, causing it to rise more quickly?

The reason for asking this is that the pH, despite just recently having to add 19 ounces of acid per day, keeps rising from 7.3 to 7.5 overnight. The CyA is 80 ppm, Borax is 50 ppm, Calcium 450 ppm, TA at 130 ppm, Salt at around 3,200 ppm, and yes I am in the process of lowering my SWG percentage to maintain a level of FC at 6 ppm. Additionally there seems to be no drop at all in the FC overnight, and no sequestrant is now being used up in a one week period, which is very, very, unusual. Our municipal water has an alkalinity of about 90 ppm.

Could it be that when I got rid of all those phosphates and scale my TDS number jumped up to a too high level, and this is creating pH issues? I do not think so as the pool is crystal clear, but just asking. What might be the least expensive way to check the TDS number?

Would you recommend any different ppm number, or set of ppm numbers, that might help?

Fortunately despite the pH rising to 7.5, 7.6 on a couple of occasions, there has been no iron staining that I can see.

Looking forward to your analysis and comments.

 

[chem geek]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

The first link talks about HEDP stabilizing PAA, but that's because HEDP sequesters iron and the presence of iron catalyzes the destruction of PAA. So the only way that HEDP would work this way with chlorine is if the iron increased the rate of breakdown of chlorine. In fact, this does occur and is why high-quality chlorinating liquid should be free of metals (see this link). Specifically, Odyssey Manufacturing notes the following:

In most cases, Iron, nickel, copper, and other heavy metal ions that catalyze bleach decomposition are below detectable levels.

The problem is that chlorine decomposition is related to concentration of chlorine so would normally be very slow in pools even with metals, but maybe that's not true and the presence of metals still accelerates breakdown of chlorine and HEDP sequesters metals so helps to prevent that (though I give another possibility later below).

As for your pH, it is rising because your TA is high. If you lower your SWG percentage on-time due to lower chlorine demand, you should find a slower rate of pH rise.

As for the sequestrant not getting used up, so not getting oxidized by chlorine, that is indeed strange. Maybe the presence of iron in the water (or something else in the water) accelerated that oxidation so now with more iron physically removed from your pool as iron phosphate and rust, the HEDP is more stable. That is, perhaps HEDP is less stable when is has no iron bound to it. I'm just guessing.

I wouldn't worry about the TDS. You are already measuring most of the major components of it except for salt and you can get a Taylor salt test (K-1766) or the AquaChek test strips for that if you want -- both will measure chloride (in units of ppm sodium chloride).

As for HEDP level, I don't know what level would be best.

 

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

chem geek,

A very interesting reply.

Your link about very pure chlorine produced by "Odyssey Manufacturing" was an eye opener. Their point about metals was illuminating, "In most cases, Iron, nickel, copper, and other heavy metal ions that catalyze bleach decomposition are below detectable levels." Interestingly the half-life of low levels of chlorine are very long. On their website they mention a concentration of 5% at 80 F being 735 days, that is a long time, and that the lower the concentration the longer the half-life. Needless to say the half-life days would be greatly reduced in an open air swimming pool, dependent on the organic load introduced into the pool, and probably the metal load introduced.

http://www.odysseymanufacturing.com/about_product.htm

It seems to be true from what I have experienced personally, in that I am seeing a much slower decomposition of chlorine than I was before. In addition, as you mentioned, the apparent large reduction in iron load, and calcium phosphate/ferric staining, appears to have reduced the metal load in my pool considerably. This has also helped to slow down the decomposition of the HEDP sequestrant significantly. In both cases maybe saving me money in the long run.

Interestingly the leaf basket's material filter has remained pure white since the last treatment, as has the skimmer and its white basket. After a normal AA treatment it would remain white only for a few days and then start to yellow long before stains re-appeared in the pool. So it appears AA with HP, and HP only treatments really do remove a considerable amount of metal, albeit it takes a number of treatments. I will see how long it takes to re-stain these items and report back at that time, if I am still with you all.

I also think that as HP can destroy iron bacteria on contact, although I also believe that the iron bacteria is in very low concentrations in the pool, that this to helped. The reason I state this is that iron bacteria can only be destroyed by chlorine at very, very, high shock levels. I guess, and it is only a guess, that part of the faster decomposition of chlorine in the past was due to it trying to destroy this bacteria, not very successfully it seems.

This then brings me to an assumption that persons who get iron from fill water, and not wind born iron will have to use larger amounts HP in all treatments, both AA with HP and HP alone, to remove the iron bacteria. This again is only a guess and would have to be proven by experimentation and observation.

Yesterday morning I turned off the saltwater cell, the FC was 8, an surprisingly today it is still 8. Yesterday the pH was 7.3 by nightfall, and today thankfully still 7.3. I will see how many days with the SWG turned off it will take to fall to a target FC of 6. Once I restart the SWG I will initially set it to 24% and see if that can maintain a FC of 6, last year it had to run at around 60% to do the same. I will report back.

As I am having success with a sequestrant level of 40 ppm I will leave it there, anyway it seems to stuck at that level.

Thank you for your help and comments.

 

[chem geek]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

It's possible you had calcium phosphate scaling in your salt cell because the pH is higher at the hydrogen gas generation plate. That would make your saltwater chlorine generator less efficient until the phosphate level got lower. However, that wouldn't explain the lower overnight chlorine loss (since I presume the SWCG is off during that time) nor the lower rate of loss of HEDP, so I think it may be more related to the lower iron content in the water (and less iron in the HEDP as well) reducing the rate of chlorine loss either from chlorine breakdown or from chlorine oxidation of HEDP.

 

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

chem geek,

Thank you for the follow-up. I would agree with you that the significantly lower chlorine usage is more probably due to the reduced metal concentrations in the pool. This, it seems, is due to the two AA and HP treatments, and other HP treatments (without AA) done at a pH of 7.3.

The reason I believe this to be true is that I am fairly good about removing the salt cell and cleaning it out, once a month, if necessary. This is done either by, shooting a strong stream of water through it if the deposits are light, or 4 parts water to 1 part muriatic acid for 20 minutes if the deposits are heavier.

Based on last summer's setting of around 60%, at power level 2, for a 5 hour run, using and SC-60 cell the daily 24 hour replacement of chlorine was around 2.35 ppm of Free Chlorine.

At its current setting of 24% the replacement figure is 0.93 ppm of Free Chlorine, a 60% reduction in the chlorine and power needed.

Here is the UV Index Forecast for Honolulu from the EPA for today, we do have some cloud cover with occasional showers. I think the link updates during the day, but for today it appears that the highest UV is 13, at 1pm.:

http://oaspub.epa.gov/enviro/uv_hou...onolulu&state_code=hi&minx=&maxx=&miny=&maxy=

I will let you know how it goes at 24%. I have not started the SWG yet at 24%, as the chlorine level despite the the SWG being turned off is still around 7 ppm.


Thank you once again for the follow-up.

 

[smallpooldad]

Re: I attempted my AA treatment

kammel78,

It seems you might have ammonia in your pool, this happened to me once, a few years ago, when doing the AA treatment. Cloudy water is very good indicator of Ammonia. It is certainly worth a check as you could otherwise be fighting this for a long time.

Ammonia if you are not adding enough chlorine to the ppms (parts per million) is hard to neutralize. It also happened to "chem geek", see his post here and how to get rid of it:

http://x.havuz.org/viewtopic.php?t=9126

You can buy an ammonia test kit from a pet store, possibly Walmart in the pet section. The test kit is relatively inexpensive, less than $10. "Chem Geeks" solution if you do have ammonia will solve your problem quickly.

He recommends for each 1 ppm of ammonia you will need 8 times the ppm of bleach (no scented bleaches).

The following numbers used are for 10,000 gallons so you will need to multiply them by 2.5.

Using Walmart's New "33% more concentrated bleach Great Value Bleach", which is 8.25% bleach, per 1 ppm of ammonia, you will require 122 ounces of bleach and 15 ounces of muriatic acid to neutralize the rise in pH.

Using Walmart's Regular Great Value Bleach", which is approximately 5.25% bleach, per 1 ppm of ammonia, you will require 191 ounces of bleach and 15 ounces of muriatic acid to neutralize the rise in pH.

If it were me in a pool of this size I would run the pool 24/7, if it is Ammonia, backwashing as necessary when the pressure builds up in the filter.

It seems as you have been adding bleach already you might be half-way to solving your issue. If you do have iron issues then keeping your pool at around 7.3 but no higher than 7.4, with sufficient sequestrant in the pool at all times it should slow down the intervals before having to do the treatment again.

This experimental method for dealing with iron issues has worked well for me especially if you have scale as well. It combines the AA method with Hydrogen Peroxide, a strong oxidizer.

See this link:

http://www.troublefreepool.com/used...g-metal-stains-results-t56485-60.html#p487143

There is no other easy method, in a swimming pool for getting rid of ammonia other than chlorine.

Good luck, and please, please, please post your results to help others in the future, be it that you do, or do not, have Ammonia. So few people post their final results after being helped.

 

[kammel78]

Re: I attempted my AA treatment

Wow, that's some good advice, smallpooldad!

Luckily, I have a reef tank so the ammonia test was quick and easy and it was negative for ammonia. Could be that I already killed most of it by dosing so much chlorine the past two days.

The HP/AA treatment is extremely helpful, especially since I know I have some scaling issues. I think I'll give that a shot next time if this treatment doesn't get all the stains.

 

[JasonLion]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

smallpooldad, there is essentially no possibility that kammel78 could have had ammonia. The behavior of his pool is well within normal behavior for an AA treatment, while there has been one post in the last 5 years where someone got ammonia any where near that quickly and it was under quite different conditions. The odds drastically favor the conventional explanations, which have nothing to do with ammonia.

 

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

kammel78,

Thank you for the kind words.

Please note that this method is very experimental ,and apart from one person no other person than myself has reported any results. And as written I strongly suggest initially it is very important to use AA with HP. The process should be started with the pool having a stating pH of between 7.2 and 7.3. The effects on the removal of scale might be directly correlated to the lower pH created by AA, 2 pounds might therefore be better than 1 pound, per 10,000 gallons.

It is still important to remove the iron sequestered by the AA and HP, into your HEDP sequestrant. This is done by letting the pH rise to 7.3 and doing an overnight HP only treatment to turn the iron into rust particles large enough for your filter to catch them, then suction vacuum the pool surfaces twice the next day to get them off the pool surfaces into your filter. Please not these paricles might be very small so although they are present on the surfaces of the pool you might not be able to see them.

If you do not do the second treatment with HP only the iron could fall out of solution and re-stain your pool.

As an ex-saltwater aquarist I was glad to see you had no ammonia, but as the saying goes "an ounce of prevention is worth a pound of cure.

However sometime back I had a question on chlorine not catching. Chem Geek was kind enough to respond and explained, in his response, that the mere fact that some chlorine was found in the tests indicated that ammonia was not present in his opinion. I had forgotten that reply so I apologize if I wasted your time.

Hope this helps and if you do the AA plus HP treatment let us know whether it helped or not.

 

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

JasonLion,

I would agree with you response the "there is essentially no possibility that kammel78 could have had ammonia".

As I stated to kammel78 in the reply above I had forgotten chem geek's answer to my inquiry, my apologies. This is especially true if pump had been running non-stop. However, and I am not trying to "flog a dead horse here", if the pump had been turned off overnight, which I do not think was the case here, and the pool water was tested from the top of the pool there exists the very faint possibility that some ammonia might be present at the bottom of the pool. This would not be detected by an ammonia test.

The reason that I believe this might be true is that, from a chemical density standpoint, water is 1g/ml, ammonia (in a saturated solution) is 1.1 g/ml (chem geek please correct me if I am wrong on this point). This small amount of ammonia would have sunk to the bottom of the pool overnight. This might only be detected if the main drain were allowed to drain for a short period of time and a sampling taken for an ammonia test.

If this was the case, the continued adding of chlorine would eventually deal with issue, slightly higher levels of chlorine being added to the pool may have resulted in a quicker rise back to normal free chlorine levels. The downside to adding extra chlorine as you are aware is the need for adding acid to keep the pH below 7.4. I find the addition of chlorine and its effect on the increase of the pH is best calculated using chem geek's "PoolEquations" Excel spreadsheet. It will give the amount of acid that needs to be added for the amount of chlorine added, to compensate for any pH rise. Perhaps adding the acid first before adding the chlorine and allowing it to mix for an hour or two might be best.

More important I think for the "newbie is the following:

I once wrote on this site that doing a shock treatment, a few days or week, before doing the AA method might help as this problem of maintain free chlorine pops up from time to time, when doing the AA treatment. You replied that you thought that was a good idea. And for "newbies" who might not have a really good handle on their chemistry I think it should always be recommended, this being especially true if "newbies" do not understand free chlorine and combined chlorine, they may not be controlling organic material as well as they should, which has, albeit, a very small chance of creating ammonia, especially if they leave the pool alone for 24 hours.

As concerns what I stated in that post in bold type I wrote he "might" want to do the test,, but "is certainly worth a check as you could otherwise be fighting this for a long time", for me, personally, I still believe in "an ounce of prevention is worth a pound of cure", but then I have an "A" personality.

Regarding your request, in your PM, to not link this discussion "Used Hydrogen Peroxide for Removing Metal Stains - Results" to newbies, I see what might be your concern, although not stated, which I think is that it is too complicated, and confusing, for persons with limited pool chemistry experience. I did not think of that, and I am in complete agreement with you, if this was your reasoning. I will not link it to "newbies", but is it OK to link it to others who are not entirely successful with their AA treatment, if they have experience? The question then remains, if it is OK to link, as to how long should they have been a member before they are no longer considered a "newbie"? I will follow the guideline that you give, be it OK to link, or not OK to link, and your parameters if OK to link.

Thank you for your remarks and guidance.

 

[smallpooldad]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

chem geek,

A interesting idea, from a person I know, regarding black algae and Hydrogen Peroxide, and a short update.

This person and I were talking about pools, he does not have one, and how a number of his friends pools, in Honolulu - especially in the windier areas, have brown-yellow stains, and some have black algae.

I explain to him as to what might be causing the brown-yellow stains, iron, or scaling, or a combination of both, and how that might be resolved, mentioning my use of Hydrogen Peroxide to remove both scale and iron. I also explained how I had gotten rid of a lot of black algae that had been in my neighbour's pool for over 2 years or so, when he was recovering in hospital for about a month. I told him that if I remembered correctly I shocked the pool for about 5 days and used to rub chlorine pucks over the black algae 2 or 3 times per day, finally eliminating nearly all of it. But that keeping at shock levels and rubbing so many spots was a real pain, and quite time consuming.

http://www.troublefreepool.com/black-algae-on-steps-need-help-t43292.html

Then he said, "Well if you used Hydrogen Peroxide in the pool, to remove scale and iron that should have gotten rid of the black algae" and was quite surprised it had not removed the black algae. I explained to him, at that time, I did not use HP (please note that aquarists use more HP than I used in my method - read below). This person keeps both saltwater and freshwater aquariums and explained to me that aquarists use HP to get rid of black algae.

Different aquarists use different methods but they are all fairly similar. Interestingly it works in both freshwater and saltwater aquariums, it seems the salt content is not a factor. Most freshwater tanks are kept at a temperature of between 70 and 78 F, and most saltwater at a temperature of 75-80 F, it could be that at temperatures above 78-80 F it might not work. The pH of freshwater tanks varies greatly depending on the type of fish being kept, being between 5.0 to 9.0, saltwater is normally between 8.1 to 8.4, it appears pH is also not and important factor.

Following are the methods employed by aquarists, who do utilize this treatment. I will list them in no particular order:

1. In still water dropping a solution of 3% HP onto the spot, in aquariums this is generally done with a small squeeze dropper. Most probably not too useful for a pool.

2. 2 ml per gallon, with fish removed, left for about and hour or so. This is sometimes used in Koi ponds. This is 10 times more expensive than the next method, but probably is very quick and effective.

3. The method he uses is 2 ml per 10 gallons, with fish in the tank, in the presence of aquarium lights. His fish do ok. He stated some persons use 1 ml per 10 gallons, and others with fish removed 3 ml.

I explained to him that light, especially UV light, turns the HP into Hydrogen and Oxygen, thereby slowly mitigating the strength of the HP, but he said it still seems to work for him, after 1 or 2 hours. He further stated that if I am skeptical that I should "Google" "Hydrogen Peroxide Black Algae", or "Hydrogen Peroxide Black Algae Aquarium". He was right there are a lot of entries for this method, with a number of "YouTube" videos, fascinating stuff.

I looked at the numbers above and came up with an HP number for swimming pools, based on 10,000 gallons. Using his method of 2 ml per 10 gallons, the amount of 3% HP required would be 676 ozs, or 21 bottles of 32 oz 3% HP, cost in Honolulu, at Walmart, 98 cents per bottle, or $20. 58, before tax. Actually one would have to buy a few more bottles to eliminate the ppms of chlorine measured before one started the treatment, to be exact 21 oz more of HP per 1 part ppm of chlorine measured.

That is might be a lot less expensive, and time consuming, than shocking a saltwater pool with a CyA of 80, not to mention hard work. If this is done without light being present, at nighttime, it is probably even more effective. So long as one remembers not to open the bottles in the presence of light. The other advantage is that it does not affect the chemical balance in any way. Even if one went to 3 ml per 10,000 gallons it would still be reasonable.

The morning following the treatment before sunrise one would still need to add back chlorine and acid.

If one used 676 oz for the treatment, but not counting the extra chlorine purchased to remove the starting chlorine, you would need to put in 32 ppm of chlorine to neutralize its effect, this would be about 861 ounces of regular 5.25 % Walmart bleach, to achieve a chlorine level of 4 ppm, nearly 5 jugs (4.7 x 182 oz jugs), plus adding 65 oz of muriatic acid to compensate for the increase in pH caused by this chlorine addition.

Whether or not this would work in a swimming pool is unknown but at this relatively low cost it is certainly worth a try. But probably more useful to persons with a lot of black algae, before one goes on the hard road shocking and scrubbing with a chlorine puck, or if one is feeling lazy. If there are only has a few spots, scrubbing with a chlorine puck, or laying the puck over the area for a number of hours, or days, would be far less expensive, and time consuming.

One other interesting point to mention is that when a friend of ours, sometime back, was getting quotes to re-plaster his pool, one of the better re-plasters at that time asked him if he ever had black algae, to which he answered yes. The plaster stated that he could not guarantee that it would not re-grow in the same area that it did before, especially if he did not maintain his pool properly in the future, as it can grow into the concrete itself, and cannot be killed easily, thereby re-appearing in the new plaster. This treatment, once the old plaster is removed, but before the new plaster is applied might lessen the chance of that happening.

Now the update for today:

Pool has not lost any sequestrant, it is still around 40 ppm. No re-staining whatsoever, alkalinity has dropped to 80, but now the pH is holding at 7.3, still using very little chlorine, as reported before, when compared to last year's usage. So all is well.

Thank you and hope you found this interesting, I did. Will it work, I do not know, but I am asking around for a pool with a lot of black algae.

 

[chem geek]

Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul

Hydrogen peroxide is an oxidizer and as such it can kill black algae just like chlorine and bromine and possibly even non-chlorine shock (MPS) can. There's no miracle here. If one has high CYA and wants to avoid adding as much chlorine, then that's what sodium bromide products do basically turning a pool into a bromine pool where the bromine is not moderated in its strength so kills yellow/mustard algae and probably would kill black algae if one brushed the heads off. The downside is that one has a bromine pool for a while.

Then there are algaecides that also can target algae growth though usually are better at preventing growth than killing existing algae. In fact, the most common algaecide for black algae is Trichlor granules. It's concentrated high chlorine at low pH so is effective as a spot treatment because it dissolves somewhat slowly.

At least with hydrogen peroxide, it's easier to recover back into a chlorine pool.

So for a treatment, hydrogen peroxide might be reasonable, but not for maintenance since chlorine alone can prevent algae growth and it's a heck of a lot easier to prevent it than it is to get rid of it once it has gotten hold.

Remember that we try and avoid the large variety of products for different purposes. Not only will shocking help against black algae, but even regular or perhaps somewhat higher target levels of FC will kill it IF one regularly scrapes off the heads -- it just takes a while. Remember that black algae generally is able to grow because the FC/CYA level is too low. We hardly ever see black algae growing in properly maintained pools. Only when the circulation is very poor. The same is generally true for green algae. It's only yellow/mustard algae that we see because it needs a higher FC/CYA ratio to prevent it from growing.