Mushrooms Growing in a Tile Shower
Since they're forms of fungus, mushrooms can be nasty and difficult to get rid of -- including those that grow indoors. One particularly tough indoor mushroom even morphs into disgusting black ooze when dying. Moisture attracts fungi, which is why mushrooms sometimes appear in showers. Preventive measures, though, such as keeping areas dry when not in use, inhibit mushroom growth.
Moisture and Removal
Mushrooms thrive where moisture is prevalent, and the only sure-fire way to get rid of mushrooms in a shower is to manually remove them and let the shower area dry. For example, after each use, allow air to flow into the shower area. Use a fan or turn on the bathroom's exhaust fan to help this process.
Cleaning and Sealing
Clean your shower regularly. Use a pH-neutral tile cleaner and a fungicide capable of killing mushrooms. Allow the area to dry and apply a high-quality penetrating sealer to grout and shower tile. Sealed tile is far less likely to allow mushroom growth.
A last-ditch DIY solution to mushrooms growing in a tile shower involves removing the grout and replacing it with an epoxy-based grout. Epoxy grouts inhibit the growth of mildew and other types of fungus (like mushrooms) that thrive in moist, dark areas.