Bromine and metal stains

[Tepelus]

First of all I want to express my gratitude towards many experts and experienced persons for the time spent for answering our questions.
I do have a question regarding the metal stains in pools or spas that are sanitized with bromine. Since bromine is a less powerful oxidizer is it less likely to get metal stains if cooper or iron is present in the water? I am using bromine, and cooper is present in the water, but I do not have any stains. I do keep the Ph at 7.4.

 

[duraleigh]

Very, very few bromine pools in the US. Not many on this forum can help.

 

[chem geek]

Bromine won't be any better at preventing metal stains, certainly not against copper stains since oxidation is not necessary to form copper stains. Copper ions are already in the form that can cause stains. It's a higher copper level and/or a higher pH that form the copper oxide-hydroxide that stains. You've just been lucky so far though your signature shows a "rubber membrane" for your pool so if that is your pool surface it may be less likely to show staining than a plaster surface anyway.

Though bromine is not as strong an oxidizer as chlorine, it nevertheless oxidizes ferrous iron to ferric iron so you would have the same risk of iron staining as well if ferrous iron ions were in the water. If you had solid metal iron, it might not oxidize (rust) as quickly with bromine compared to chlorine, but usually one does not find solid iron in a pool. Bromine might have stainless steel (which contains iron) corrode more slowly, but better stainless steel (316 vs. 304) is usually used in pools and normally does not corrode unless salt levels are very high and/or oxidizer levels very high or pH low.

 

[Tepelus]

Thank you for your answer Chem Geek. You made things clear for all of us.