Cleaning and Stain Removal - Mildew stain on carpet?

Does anyone know how to get a mildew stain out of carpet? We took down our tree & evidently, I overflowed or spilled the water when putting it in the tree base. Soooo, water has been trapped underneath the plywood we had under the tree stand for who knows how long.

I'd appreciate any advice or tips to get this black stuff off my carpet. I'd hire a professional to clean our carpets but money's a bit tight right now, kwim?

Thanks! :)

depending on how your carpet was installed...this is what i suggest

If your carpet has padding underneath..the water has most likely entered into the padding and onto the subfloor. To completely remove this..the best way would be to pull the carpet back..cut out and replace padding..after cleaning of the subfloor and sealing if needed.

If this is not a option..leave the area open to the air for serveral days before cleaning. Let all the moisture dry.

then get a protein or enzyme cleaner..apply to a area larger than what you see..let it sit 10-20 mins..do not let dry..take a shop vac afterwards and rinse area with hot water...this may take serveral applications..afterwards let area dry before placing anything on top of it for a few days...if you have a reoccurance of the mildew it means the padding and subfloor are still wet....that is why my first suggestion would be the best recourse

You could try docduck's 2nd suggestion first, since it's the easier of the two, but I think ultimately you're going to have to go with the first one to get the job done right. Carpet padding does not handle being wet well.