Removing Metal stains

[MartyW]

I ordered stain remover on line assuming it was ascorbic acid, but it is oxyalic acid instead. (I also ordered ascorbic acid from the supplier in mbar's sticky). Can I use this and do I follow the same procedure as ascorbic acid?

Thanks for your help

Marty

[waterbear]

yes
However, ascorbic acid is toxic so be careful. FYI, you can also use citric acid.

[MartyW]

Thanks for the reply. I assume you mean oxalic acid, not ascorbic acid ?

Marty

[CarlD]

Yeah, ascorbic acid is Vitamin-C

[waterbear]

Originally Posted by MartyW

Thanks for the reply. I assume you mean oxalic acid, not ascorbic acid ?

Marty

yep, blonde momemt! (I refuse to say senior moment!)
All three will remove some, but not all metal stains (some copper stains are just about impossible to remove).
Ascorbic acid is the safests but the most expensive and it's price has gone up a lot lately. Oxalic acid is the least expenisce and is found in some commercial products such as United Chemical's Pool Stain Treat but is it very toxic and somewhat corrosive. Citric acid is just slightly more expensive than oxalic acid and is much more benign but still more irritating than ascorbic acid but not considered a poison.

[MartyW]

Should I be backwashing my DE filter during this process? Is there a way to eliminate the metals other than a complete water change?

Thanks, Marty

[waterbear]

Originally Posted by MartyW

Should I be backwashing my DE filter during this process?

Only if your filter pressure rises too high.

Originally Posted by MartyW

Is there a way to eliminate the metals other than a complete water change?

Basically, no, assuming there are no metals in the fill water. If you REALLY know what you are doing you can sometimes get them to 'stain out' on the filter media and then change out the media (DE in your case) but it's tricky at best for someone who really understands the chemistry involved and NOT something to try if you don't.

Originally Posted by MartyW

Thanks, Marty

Welcome!