A 30-Second Test For Seeing Whether Your Home Has Mold

Open the lid of your toilet tank and check the undersides. If there is mold there it could mean you have mold somewhere in the house that provides the spores you need to grow in your toilet tank.

When you check your toilet you might think, "But it's wet and dark. It seems like it has mold …" Not really! You are much less likely to find mold in the toilet tank than in other damp areas like the shower. The fuel cap itself is heavy, but not hermetically sealed, which means it doesn't allow for a great deal of air exchange.

Such little airflow means it's not impossible for a malicious mold spore to find its way inside, but the chances are pretty slim. However, colonized molds in a house release a large amount of spores into the indoor air – much more than would be naturally present. More spores mean the chances of mold forming in the tank increase. Because of this, checking the toilet tank regularly can help alert you to a bigger mold problem in your home. When it's inside, there were enough spores in the air to opportunistically find their way to your toilet to grow.

The type of mold in toilet bowls depends entirely on what types are present in the house. Aspergillus or Penicillium are some of the most common, but with so many species identified so far, any species could be present. Such a wide variety of species also means that the mold inside the toilet bowl can be a variety of colors, from pink or brown to black and green, as well as a range of textures, such as velvety or powdery.