Re: Used Hydrogen Peroxide for Removing Metal Stains - Resul
I re-wrote the instructions to make them clearer.
Hope this helps.
"The Hydrogen Peroxide and Ascorbic Acid Method - Operational Guide"
I believe from personal experience and observation the two main advantages of using Hydrogen Peroxide as an addition to the Ascorbic Acid Method is that it removes iron from the pool (not just putting it into solution) and it can remove scale.
1. It removes scale via backwashing from the pool, acid washes are not required.
Acid Washes, in my opinion, should be avoided at all costs as they are dangerous to do unless you know what you are doing and are in my opinion too aggressive for most plaster pools. It would be better to empty your pool have it “shot blasted” with baking soda, but not glass beads as I feel this is also too aggressive
2. It physically removes the iron from the water (The AA treatment does an excellent job of lifting the iron stain from the pool surface, and dissolves/sequestrates the iron stain into the water.
But it does not remove the physical iron)
Scale, be it calcium, iron, or phosphate scaling is the real underlying issue with iron stains as the scale, because it is tacky, acts as a kind of trap/magnet to these metals not allowing the regular HEDP sequestrant to do its job fully. This is my opinion and will only be proved over the next six months, or year or so. But I do now have a very white scale free pool.
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 Very Important Note on Sequestrants
The only type of sequestrant to use in this process is a “HEDP” based sequestrant.
The three this forum currently recommends are “Jack’s Magic Purple Stuff” for SWG pools, and “Jack’s Magic Pink Stuff” for non-SWG pools, or “Metal Out”. I have been very happy with “Jack’s Magic Purple Stuff”, “Metal Out” is not available to my knowledge in Honolulu.
Do not use EDTA based sequestrants as number of papers have mentioned them as inferior in their ability to hold up in this type of sequestration.
Do not use polymer based sequestants for the same reason.
Do not use sequestrants that do not have a material safety data sheet (MSDS), it could be flocculant based and this might interfere with the ability of the Ascorbic Acid to dissolve the iron from the stain.
An MSDS sheet will tell you if HEDP is being used and at what percentage, you are looking for 20% or more.
If you did use a flocculant based liquid, or an unknown non-MSDS liquid, wait 2 weeks before attempting to try the "The Hydrogen Peroxide and Ascorbic Acid Method”, in order to remove it from the water.
An Analogy of the Method
Another way of thinking of this is what happens when you clean an iron tool of rust. After you remove the rust from the surface it is nice and shiny again, but over time the iron oxidizes to rust and your stain reappears. With Ascorbic Acid you have removed the layer of rust so the pool looks clean but underneath is calcium and iron scale and perhaps phosphate scale, this then rusts again and despite little iron being added to the pool you get re-staining.
With the addition of the HP method (removes scale and iron) to the excellent AA method (which dissolves iron and perhaps other minerals so that HP can more easily remove it with the aid of the sequestrant) you are removing the problem garden tool (think scale) as well as the rust nearly completely, so hopefully it will take a long time for stains to re-occur.
In addition those pools where the AA method is not completely successful, the primary reason in most cases is a form of Calcium Scaling, maybe with a mix of iron or phosphate or both.
Let me state right from the beginning that using a slightly modified "Ascorbic Acid Treatment" with the "HP Method" to my way of thinking should be far superior to just the "HP Method" alone because of the Ascorbic Acid's ability to make iron dissolve so that it can then be sequestrated by the HEDP and then re-constituted by the HP for removal.
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A Cautionary Note
Firstly this has only been tested on a saltwater pool, indications are that saltwater helps this process. Freshwater chlorinated pools have not been tested so if you do this method in your freshwater please post your results for others to see, thank you.
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.
Also for this to work you do need to have either iron, manganese, and copper, or their oxides and/or orthophosphates in sufficient quantities for it to work (quantities as yet unknown) as the aforementioned ingredients act as a catalyst to the Hydrogen Peroxide. Without these ingredients in high enough levels it might not work.
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.
When adding the HP do so only in darkness, sunlight destroys it as does light from electric bulbs. Do not pre-open the bottles in the presence of light. Do not turn on your pool lights or outdoor lights at any time during the process. A Moonless night is preferred.
A Point to Think About
Please remember this may take 1, 2, 3, or four treatments before all is done. It will not get rid of underlying organic stains (organic staining underneath scale) for this you will have to wait 4 to preferably six weeks to shock your pool for 1 to as long as 5 to 7 days, possibly longer if there are a lot of organic stains, or if they are deeply imbedded.
The Process:
Please read twice at a minimum before proceeding.
Make sure your pool is properly balanced, and that you have used a proper test kit whose chemicals are not out of date. When adding chemicals to the pool try to walk around the entire pool pouring them in slowly this should ensure you do not have too high a concentration in any one area.
Do not pour anything through the skimmer. The pump must run through the night in filter position. 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.
The two recommended test kits are:
The kit available on this forum, and the Taylor test kit.
1. The colder the better, anything under 77F should work, under 70F will be much better.
2. Bring HEDP sequestrant level to 42 ppm. two bottles of "Jack's Magic Purple Stuff" per 10,000 gal. I do not know the quantity for "Metal Magic".
3. If using Ascorbic Acid (Highly Recommended) then make sure the pH is 7.2 - 7.3, if not using Ascorbic Acid lower pH to 6.8. ph lower than 6.8 is recommended for better results.
Ascorbic Acid deteriorates (loses its potency) over time so check its “good by date”. Personally I grind up “Walmart Vitamin C with Rose Hip –Non-Buffered” tablets as Vitamin C is not readily available, except by mail, here in Hawaii.
4. The 3% Hydrogen Peroxide (32 oz bottles from Walmart are the least expensive in Honolulu) amount is 221 ozs for each 10,000 gallons plus the pre-treatment chlorine ppm level times 21 ozs, if you are using 27% HP then divide these number by 9. Pour this around the pool, not through the skimmer. Preferably allow your pool cleaner to mix it. The total amount of HP required, if the starting chlorine level is 6 ppm, would be 11 bottles of 32 oz 3% HP.
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)
5. Do not use Thiotrine to lower your chlorine levels the HP does that and also acts as a sanitizer, albeit not as good as chlorine.
6. The higher the Hydrogen Peroxide % the faster it loses its effectiveness over time, so check the "good by date" or "expiration date" do not use old bottles, or ones that have been sitting in the pool store collecting dust.
7. Do not use Algaecide 60, make sure you Free Chlorine is holding with less than 0.5 difference, before effecting the treatment. Well you could use Algaecide 60 but I think it might interfere with the HP and you will need more chlorine later to get your pool back to the right level of Free Chlorine.
8.
(Very Important) Add the HP in darkness, sunlight destroys it as does light from electric bulbs, allow it to mix in your pool for two hours (it takes that 2 hours before it will start to work in the water) before adding Ascorbic Acid, after 2 hours at a rate of 1lb minimum (for heavily stained pools 2 lbs would be good) for 10,000 gals. Remove pool cleaner before adding Ascorbic Acid, or if not using AA still remove it.
9. The HP only is effective for up to 7 hours after that it stops doing its job so (Very Important) before sunrise add 2 "182 oz jugs" of Plain Liquid Chlorine/Bleach per 10,000 gals to get your chlorine levels up to about 8 ppm, to avoid an algae bloom.
If you only use Hydrogen Peroxide and no Ascorbic Acid immediately add 30 oz of Muriatic Acid by walking around the pool to minimize local high concentrations. This should bring your pH down to 7.1. The reason for this is that chlorine raises the pH.
Important Note if also using Ascorbic Acid
The pH will be lower than 7.0 even with adding 2 "182 oz jugs" of Plain Liquid Chlorine/Bleach per 10,000 gals remember to add a Borax to up the pH to 7.1.
15 oz of Borax will raise pH 0.2 per 10,000 gals.
Then check your chlorine levels after 4 hours to adjust, if too high they will go down. This insures you will not get an algae bloom.
8. Never continue the treatment into the next day as Hydrogen Peroxide is destroyed by sunlight and you do not want to get an algae bloom.
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 if you do not have a suction side cleaner, and backwash it again in the evening.
10. You can repeat this treatment again that same night if nearly all the stains appear not to be totally gone (by this I mean a really white pool for plain white plastered pools), and again the next day.
Also you might need to add sequestrant, you will only know this if you have a sequestrant test kit, get this directly from "Palintest", 1-859-341-7423, it is less expensive and the chemicals solution will be current for 2 years. If no test kit, add one more 32 oz bottle of sequestrant. If you live in say West Texas, or Hawaii, and have really, really bad scaling issues you may be looking at a number of repeat treatments, but I would still prefer this over an acid wash any day as this is far less damaging to the pool finish. And yes I have had an acid wash, and never ever again will I do that.
Note: Strongly recommend you do not buy sequestrant test kit from pool store as you will have no idea how old the sequestrant testing chemical "Thorium Nitrate" is, useful life is 2 years.
11. Wait 4 days after treatment to check your CyA reading as it may give you a false low reading, by this I mean 80 ppm may only read 50 ppm for a few days, although you actually have 80 ppm, of which 30 ppm went dormant but will return.
Now How to Remove Most of the Iron from the Water
The reason for doing this final treatment is to remove as much iron from the pool, and or scale from the pool by backwashing. The removal of the iron you have just sequestrated into the HEDP is more effective at a pH above 7.0 or higher, the reason for not going above 7.3 or 7.4 is that the sequestrated iron will fall out of solution and re-stain the pool. When you add HP at the levels of 7.3 or 7.4 it converts the sequestrated iron that is in solution to rust particles large enough for your filter to catch them and the be backwashed, although this partially occurred when you used the AA. The estimated removal percentage is 70% or higher according to researchers.
This just removes most of the remaining iron and it is highly recommended to do this additiona/final treatment.
1. Let the pH rise to 7.3 but no higher than 7.4.
2. Again as before in darkness add 221 ozs for each 10,000 gallons plus the pre-treatment chlorine ppm level times 21 oz, if you are using 27% HP then divide these number by 9. Pour this around the pool, not through the skimmer. Preferably allow your pool cleaner to mix it.
3. The HP only is effective for up to 7 hours after that it stops doing its job so (Very Important) before sunrise add 2 to 2 1/2 to 3 "182 oz jugs" of Plain Liquid Chlorine/Bleach per 10,000 gals to get your chlorine levels up to about where they were before the treatment, to avoid an algae bloom.
Immediately add 30 oz of Muriatic Acid by walking around the pool to minimize local high concentrations. This should bring your pH down to 7.1. The reason for this is that chlorine raises the pH
4. Then check your chlorine levels after 4 hours to adjust, if too high they will go down.
5. 3 hours after sunrise backwash your filter, then backwash it again in the evening.
This process is also useful as a periodic treatment for those that have wind-blown iron, say once every 3 to 6 months, or as necessary.
Ongoing Monitoring
I still think it a good idea to keep some of Jack's HEDP product in the pool, perhaps 20 ppm, or 40 ppm if you have a lot of wind born iron, be it the Pink or Purple Stuff, the reason being it acts as "The Canary in The Coal Mine", if one suddenly sees the usage go up it would be a good indicator to just do the HP treatment alone at say 7.3 or 7.4, if the pool has not stained. This would save one from having to buy Ascorbic Acid. For peace of mind, if the usage of the HEDP sequestrant is low, then it might be a small long-term expense worth bearing.
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.
As I have written before I think a "Sequestrant Test Kit" from the company "Palintest" is a "must have" if iron, or other metal staining/scaling, is your ongoing problem.
A Simple (Non-Staining) Way to Add Borax
Add Borax by sifting it through a wire colander into a large bowl, then fill a 16 gallon tub with about 12 gallons of water by the side of the pool, then add the 76 oz of borax and stir it vigorously and immediately pour it around the pool in a small bucket. It seems to mix into the pool without leaving any trace, and avoids the issue of localized high pH. But you must make sure your pool cleaner is put back in to stir it up.
Additional Borax note:
If you want to neutralize the Borax to effect the "Adding Borates to Your Pool" you can pour 36 oz of Muriatic Acid
only after 12 gallons mix of water and 76 oz of Borax have been mixed as mentioned above and stir that with a spoon. When I do this most of the powder dissolves and the pH of this adjusted water is hand safe. This then becomes pH neutral as far as the pool is concerned so again no issues with localized high pH .
Warning: Never add water to acid only acid to water
My Personal Experience
Is that if you have been using an HEDP sequestrant for a long time you probably have fairly high orthophosphate levels, so the first treatment with AA might only work primarily on getting these levels down with some effect on the of iron, manganese, and copper stains. However you might get lucky due to your particular water and it might go for the iron and not the phosphates first. The use of Ascorbic Acid will help a lot in the removal of metal stains more so than just HP alone, these will then either oxidize or be removed by the filter backwash.
The second treatment if necessary, with AA will do the same again but this time it will work more on the scaling issues.
The third treatment if necessary, with AA should have gotten rid of most if not all the calcium, calcium phosphate, or iron phosphate scaling. And it seems to me that the iron is gone and I do mean gone I do not think it is even in solution in the sequestrant, or if present there is very little there.
The fourth treatment “How to Remove Most of the Iron from the Water”, will remove most of any remaining iron from the pool and some scale.
If you have not been using an HEDP sequestrant then maybe 1 or 2 treatments might work, instead of the first three.
After this if you have iron issues from wind born sources then use the balance shown below for a pH of 7.3, if no wind born source then keep the pH in normal range balance, unless of course you use a lot of fill water with iron. Try to keep your CSI in negative numbers around -0.10 to -0.20. I believe that keeping a slightly higher alkalinity number also helps with scaling, so if you had to choose between higher alkalinity or higher calcium go for higher alkalinity. Also continue using an HEDP sequestrant if wind born, if fill water you may be able to get away with no or little (10 ppm) sequestrant.
I keep my numbers for a SWG pool with wind-blown iron as follows, strangely keeping the alkalinity at 130 ppm, keeps the pH from rising too fast if it falls to 120 or 110 the pH starts to rise, why I do not know. Please be aware that water chemistry does vary from place to place, the higher alkalinity may not work in your water:
Cl 4
pH 7.3 (to avoid iron staining and have -0.1 pH as reserve insurance)
TA 130
CH 475
CyA 80
Salt 3,200/3,300
Borates 50
Phosphates 2,500 (High levels are not an issue if chlorine, pH and CyA are maintained at appropriate levels)
HEDP Sequestrant 42 ppm
Temp 78F – 83F
Gives a slightly minus CSI of -0.13 at 78F, and -0.09 at 83F
Also as chem geek wrote if you do not have a dog that drinks from the pool
(borates can kill a dog) adding borates to a level of 50 ppm will help you maintain a relatively stable pH despite an SWG, heater, and higher alkalinity, some or all of which might cause your pH to rise quickly.
Hope this helps.
