brown stains

[Guest]

I've been getting these brown spots on my pool liner and they won't rub off. I was wondering if anyone knew what they might be.

[bj]

We have a lot of dark stains since we went from chlorine to an ionizer. They come from fungus growing on the ubderside of the liner. We have gotten no good solution for the problem.

[Gov]

Are these brown stains on the pool floor or walls?
I seem to be getting these too!
They are only one one side of my pool, on the pool floor.
They range from about 5mm to 15mm in dia.
I tried scrubbing them with a scrub brush, they lighten some but wont go away.
Does any one know what this is and how to get rid of it?

[dbrookes]

Have you tried shock treating the pool with Chlorine? Brown stains can be caused by osmosis. If this doesn't work it's a case of emptying scrubbing down with acid mixture and washing down. Sometimes rubbing a chlorine tablet on the stain without disturbing the water works.
Darren

[Pool Helper]

Often stains that appear in the pool are actually indicative of algea growth under the liner.

If this is the case, liberally sprinkle iron sulfate (also called ferric sulfate or copperas) around the soil at the edge of the pool or deck. Water it in well. After some time it will work its way down under the liner and kill the offending alga.

This is not a quick fix but will work in the long term. Immediate results may be achieved by shock treatments.