Brown stain in pool spa

[Dan Campbell]

I'm trying to determine if the brown stain in my spa is algea, iron, or what ever. The stain formed while the pool was closed and no water was in the spa. Last winter after rain and snow melt made it necessary to empty some water out of the pool, I forgot about it and pumped a little more out than I wanted. Enough to take it below the spa floor. I didn't add any water and when it was time to open the pool there wasn't enough rain to bring it back into the spa. The spa was dry and it had this brown stain all over the plaster. We have always had a little brown around the drain in the bottom of the pool but generally most of the pool is not affected.

We have tried super shocking the spa by itself and lots of scrubbing. It has reduced some over the summer but mostly it is still there. Any thoughts?

Thanks - Dan

[Guest]

Vitamin C aka ascorbic acid. Rub it on the stain. If it goes away it's iron. Try that and report back.

[curtisG]

Vitamin C aka ascorbic acid. Rub it on the stain. If it goes away it's iron. Try that and report back.

I had the same problem with my below ground pool, and doing the Vitamin C test did make the stain go away.

What chemicals do I need then to correct this Iron issue go away?

Thanks

--curtis

[Backglass]

What chemicals do I need then to correct this Iron issue go away?

Any pool store will have "sequestrant"...usually called "Metal Out", "Metal Magnet", or some such. It's specifically for getting metals out of solution so they can be filtered.

[curtisG]

Any pool store will have "sequestrant"...usually called "Metal Out", "Metal Magnet", or some such. It's specifically for getting metals out of solution so they can be filtered.

Thanks for the feedback!!

--curtis

[curtisG]

Any pool store will have "sequestrant"...usually called "Metal Out", "Metal Magnet", or some such. It's specifically for getting metals out of solution so they can be filtered.

On a related question to the presence of Iron in my water...

I have no metal parts (other than the heater core in my MiniMax 400) that touch the water (i.e. no ladders, slides, etc...). So how does a build-up of 'metals' happen in a pool? I have a gunite inground pool if that matters.

--curtis

[Buggsw]

Your fill water could have metals in it, especially if it is well water.

You could have been using copper based algaecides.

Your pool store shock could have copper in it.