3 Met O Plus and metal stains

rcy · Jul 27, 2014

I've been battling metal staining in my pool for most of this season. Ascorbic Acid in the form of vitamin C works well and so does Citric Acid (Natural Chemistry Stain Free for example) in removing the stains. The local pool store suggested 3-Met-0 Plus by Sani Marc (note 3-Met-0 is a liquid sequestrant, the 3-Met-0 Plus is a powder). The label mentions that it 'contains' Sodium Bisulphate. This video shows it doing an impressive cleaning job - http://www.youtube.com/watch?v=AUClby0bVGU

Does this stuff have any benefit or drawback compared to Ascorbic/Citric Acid? Does it consume chlorine like the Ascorbic/Citric?

Thanks.

chem geek · Jul 28, 2014

Sodium bisulfphate is dry acid so nothing special there -- it just lowers pH. There may be other chemicals in it but I can't find an MSDS so I can't tell you about it.

rcy · Jul 29, 2014

Thanks. I couldn't find an msds either. There must be something else in there then besides the sodium bisulphate. I'm wondering if it's just ascorbic or citric acid (the video looks a lot like what happens when those are added to a stained pool) with the sodium bisulphate to lower Ph to prevent the stains from reappearing.

rcy · Apr 7, 2015

Well I have an msds. Anyone know what this stuff is and any plus or minus compared to ascorbic acid? . Thanks.

Main ingredients are

2,3-didehydro-D-erythro-hexono-1,4-lactone

and

sodium hydrogen sulphate.

JasonLion · Apr 7, 2015

2,3-didehydro-D-erythro-hexono-1,4-lactone is the mirror isomer of ascorbic acid, and so will do the exact same thing for our purposes.

Sodium hydrogen sulphate is what we call dry acid. It lowers PH with no specific stain removing properties.

Since you are getting less than 100% ascorbic acid, you will need more of this stuff than you would of ascorbic acid.

rcy · Apr 7, 2015

Thanks for the reply. I guess they add the sodium hydrogen sulphate to lower the pH and reduce the risk of staining - however, I'm quite happy with my pH level where it is. I wish bulk ascorbic acid was easier to source here in Canada. Do you have any idea why they would use the mirror isomer instead of just using ascorbic acid? Is it cheaper or more effective? I'm not a chemist, so I had to Google mirror isomer...lol.

Also, so many different names and formula for the same thing - I think the 2,3-didehydro-D-erythro-hexono-1,4-lactone is also known as Sodium Erythorbate (mentioned once in an old thread here http://www.troublefreepool.com/threads/19968-Using-Sodium-Erythorbate-for-Stain-Removal )

chem geek · Apr 7, 2015

It may be cheaper though as far as I can tell ascorbic acid seems less expensive online. And yes you are correct that the chemical is also known as sodium erythorbate.