A certain mold, called pseudomonas aeruginosa causes staining and separation of the nails, and is frequently experienced by people who wear false nails because of the moisture trapped in them. If you have nail problems, you can try the remedy for this mold, which is to soak your nails in apple cider vinegar twice a day for five minutes. In a couple of weeks, the mold and problems may disappear, but it's recommended that you soak in vinegar even after the problem is gone as a preventive measure. If you try the vinegar soak and still have problems, you may have a fungus and will need over the counter nail fungus medication. If this doesn't work, you should see your doctor for something stronger.