Solution for iron problem

TheMartin · Postby **TheMartin** » Mon 19 Mar, 2012 15:57

I don't know that much about chemical formulas but I can tell you this for my experience and experiments with my 8000 gallon pool:

- The hydrogen peroxide does remove stains, but for some reason, some stain will remain in the joints of venetian.
- If you use 250vol hydrogen peroxide, very little of this is needed to react with 10 liters of hypochlorite.
- When hydrogen peroxide mixes with hypochlorite in the water, you can see the oxigen (and probably some other gas) being released in very little bubbles.
- This solutions gave me by far the best results to maintain my pool, just make sure to give the pool a hypochlorite shock at least once a week to kill all water-life. This solution is probably not good for public swimming pools where a lot of people swims and you need an effective killing agent constantly acting in the water so that diseases/bacteria/etc are not spread. This would be because even though hydrogen peroxide kills many organisms, it's not as effective as hypochlorite in killing every-thing.

Postby **chem geek** » Mon 19 Mar, 2012 21:43

TheMartin wrote:- If you use 250vol hydrogen peroxide, very little of this is needed to react with 10 liters of hypochlorite.

The rough rule of thumb is that it takes the same volume of 3% hydrogen peroxide to neutralize 6% bleach. So if your hypochlorite is 12.5% chlorinating liquid and the "250vol" is 25%, then it takes (12.5/6)*(3/25) = 0.25 or 1/4th the volume of 25% hydrogen peroxide to neutralize 12.5% chlorinating liquid. So in your example, it would take 2.5 liters of 25% hydrogen peroxide to neutralize 10 liters of 12.5% chlorinating liquid.

TheMartin · Postby **TheMartin** » Wed 21 Mar, 2012 09:24

Correction, 250 vol. would be around 75% hydrogen peroxide.

cheers

Postby **chem geek** » Wed 21 Mar, 2012 21:54

Are you sure about that? Most hydrogen peroxide for commercial use isn't any higher than 30% since higher concentrations are much less stable. Baquacil Oxidizer is 27% hydrogen peroxide, for example. Check the ingredients list of the product you are using to see what it says for the percentage of hydrogen peroxide.

TheMartin · Postby **TheMartin** » Thu 29 Mar, 2012 16:35

Chem,

From wikipedia (http://en.wikipedia.org/wiki/Hydrogen_peroxide):

A common concentration for hydrogen peroxide is 20-volume, which means that, when 1 volume of hydrogen peroxide is decomposed, it produces 20 volumes of oxygen. A 20-volume concentration of hydrogen peroxide is equivalent to 1.667 mol/dm3 (Molar solution) or about 6%.

If you do the conversion, 250vol should be 75%

Postby **chem geek** » Sun 17 Mar, 2013 20:08

I'm cross-linking this thread to this TFP thread where an experiment was done to remove metal stains using hydrogen peroxide and it appeared to work very well.

azulverde · Postby **azulverde** » Mon 15 Jan, 2018 03:50

Before you go ahead implementing this method, you should first backwash the filter.
Calculate how much flocculent you should add. Usually, for every 6,500 gallons of water, it is suggested to add one quarter of a gallon of flocculent.
Then, add flocculent to the waters so that it mixes with the water to attach itself to the iron. Once it attaches to the iron, it pulls the iron to the bottom of the pool. This way, it collects on the floor of the pool.
Remove the collected metal on the floor. Since it settles on the floor, it would be very easy for you to remove it.

Teapot · Postby **Teapot** » Mon 15 Jan, 2018 05:58

If using that method, you need to use the right flocculent. To flocc metals (positive charge) you need an anionic flocculent (negative charge) to pull the charged particles together.

To be honest that method is long winded and requires more chemicals. Sequestriants are short term as the chlorine is used up to break them down so using more chlorine, likewise with algaecides, but hey that's what built the pool industry!

Better to filter the iron out. A really good filtration media like Activate from Dryden Aqua has a negative surface charge so will attract iron. Simply reduce the iron in the pool with ascorbic acid from the staining version back into solution non staining. Then put a chlorine source into the skimmer to re oxidise it just before it enters the filter. The iron will plate out and be grabbed by the filter media and you'll need to frequently backwash the filter and repeat until the iron is depleted. You can measure the iron in the backwash water to prove it's working.

bwiatr03 · Postby **bwiatr03** » Tue 18 Sep, 2018 20:26

Hey I get that you guys know about this stuff in great detail but I don't have all this chemistry background. I have an above ground pool that holds 4800 gallons of water. What product can I buy to get the iron out of my pool? I appreciate your intelligence but I just need a specific straight answer if you could, please?

Teapot · Postby **Teapot** » Wed 19 Sep, 2018 09:51

My post was a straight answer

David_Pool · Postby **David_Pool** » Mon 08 Mar, 2021 05:42

Dear

chem geek

,
I routinely use hydrogen peroxide for metal removal.

Is the chemical reduction process towards iron oxides and hydroxides stains confirmed by any studies?

Excuse me for retrieving a post from so long ago.

Postby **dynamictiger** » Mon 08 Mar, 2021 16:39

For readers interest:

Hydrogen peroxide is not approved for commercial pool use in Australia other than South Australia.
Recently the APVMA retracted labelling permission on Peroxide for pool use - this doesn't stop it being sold domestically
The ruling was overturned by the Supreme Court
Watch this space I think

As for using Hydrogen Peroxide as a sanitiser personally I wouldn't do so. There are a range of pathogens that are not only resistant to it but encouraged by it as I have read. Its been a little while however I was contacted by a pool in SA who had a specific microbe infection on reading up this specific bug is encouraged by peroxide. As I recall it this specific bug was in the SA code for monthly testing as it is known as a weakness and is totally eradicated by chlorine.

In the reading and thinking, whilst I dont know this, I speculated the peroxide would not be effective against any of the microbes that occupy the biofilm particularly inside the pipe works.

David_Pool · Postby **David_Pool** » Tue 09 Mar, 2021 04:14

dynamictiger wrote:For readers interest:

Hydrogen peroxide is not approved for commercial pool use in Australia other than South Australia.
Recently the APVMA retracted labelling permission on Peroxide for pool use - this doesn't stop it being sold domestically
The ruling was overturned by the Supreme Court
Watch this space I think

As for using Hydrogen Peroxide as a sanitiser personally I wouldn't do so. There are a range of pathogens that are not only resistant to it but encouraged by it as I have read. Its been a little while however I was contacted by a pool in SA who had a specific microbe infection on reading up this specific bug is encouraged by peroxide. As I recall it this specific bug was in the SA code for monthly testing as it is known as a weakness and is totally eradicated by chlorine.

In the reading and thinking, whilst I dont know this, I speculated the peroxide would not be effective against any of the microbes that occupy the biofilm particularly inside the pipe works.

I don't see any relevance to the topic covered in your response.

My question is purely accedemic about the reaction of hydrogen peroxide with iron.

The fact that in some countries it is or is not a biocide has nothing to do (in Europe you can use it for water treatment).