gunite stains

[alupher]

we have a SWG pool that was installed in 84. The finish isn't smooth the previous owner said they had it acid washed once. there is a orange-brown stain on the walls and sides of the pool that we are trying to get rid off. scrubbed it last year with vitamin-C, pumice, clorox tablets and were unable to remove the stain.

I have drained the pool and an getting ready to scrub the pool. Question is whether we should use water/soap/bleach mixture or muriatic acid.

Or is there a better way to proceed?

regards,

andy

[PoolDoc]

Acid washing destroys pool surface, removing the stain, but leaving the plaster rougher, thinner, more porous, and thus more susceptible to stains!

Try using Iron Out -- you can get a bottle at Walmart in the detergent section -- and see if that helps. If Iron Out doesn't remove, or at least lighten it, it's probably NOT a metal stain.

If Iron Out does work, you may want to get a larger quantity from Amazon:

Super Iron Out IO30N Rust Stain Remover, 30 oz (http://www.amazon.com/gp/product/B0014X7B22/poolbooks)
Super Iron Out IO65N Rust Stain Remover, 65 oz (http://www.amazon.com/gp/product/B00103XAQC/poolbooks)

The larger size ships from Amazon, so if you get the 1 month Amazon Prime (http://www.amazon.com/gp/prime/?tag=poolbooks) trial, you can have it shipped 2-day for no extra charge.