Well, just the title of this article sounds gross because no one likes mold, but unfortunately it is a problem that is encountered far too often by hot tub owners, many who don’t even realize that is they may have a mold problem.
It is very important to clean your hot tub cover regularly to not only avoid dirt and dust build up but also mold and mildew growth. Dirt and dust on your cover may not seem like a big deal as it really does not affect your cover, but it will affect your hot tub water. Dust and dirt build up on your cover will eventually transfer to your water which will in turn cause bacteria to grow in the moisture and build up on the bottom side of your hot tub cover causing mold and mildew growth.
When mold and mildew build up in your cover it will eventually cause the cover to stink. We often hear from customers who state they are doing everything right with their water but are still getting the awful smell. If you are changing your water every 3-4 months, cleaning your filters with Filter Cleaner, and balancing your chemicals regularly chances are the smell is coming from our hot tub cover due to mold.
In this case your hot tub cover needs to be cleaned. This can be done with a cover cleaner mixed with water, it is not recommended to use household products on your cover as they can get into the water and cause problems with your chemical balance. The only exception to this would be if there are physical dark or black splotches of mold that you can see.In this case you can use bleach diluted in water to wipe the cover down, this will help kill the mold. You may also want to remove the vinyl from the cover and wipe down the foam core to ensure the mold is removed.When you are done with the bleach solution be sure to rinse everything VERY well with clean water to ensure there is none left that may cause problems in your tubs water.
Once your problem is taken care of the only way to be sure to avoid the problem again in the future is to clean the cover regularly (approximately every 2 months) by using a cover cleaner solution and water, this will also help extend the life of your cover and keep it mold free.