Why Is There Black Mold In My Hot Tub?

The sight of mold may understandably make you feel uncomfortable at home. However, many people don’t expect to uncover their hot tub and find black mold. So, why is there black mold in my hot tub?

Black mold forms in hot tubs because of the darkness, warmth, bacteria, and condensed water. Mold is more likely to form if you don’t regularly uncover the hot tub for 30 minutes at a time and clean it. Biofilm and white mold can also form in a hot tub due to poor cleaning habits, so you must treat the water weekly.  

Remember to clean the underside of your hot tub cover as that is a common spot for black mold to grow. Don’t get in the water if you find black mold or biofilm in your hot tub or on the cover. Follow along as we explore why there is black mold in your hot tub and highlight easy solutions. 

What Causes Black Mold In A Hot Tub?

1. Neglect

You will likely find mold in a hot tub that you rarely use. That’s especially true if you rarely remove the cover to let your hot tub breathe, so to speak. A covered hot tub that’s full of hot water is a perfect breeding ground for black mold.

However, this isn’t as much of an issue if you regularly use your hot tub. Mold is less likely to form if you frequently treat the water, remove the cover, and get in. The longer a hot tub stays covered, the more likely black mold will grow.

That’s because of the mixture of darkness, moisture, and warmth, which is perfect for black mold. Ideally, you should uncover your hot tub for at least 30 minutes each time you treat the water. This can significantly reduce the risk of black mold.

2. Unsanitary Water

Hot tub maintenance is quite demanding, but you must keep up with it to ensure your hot tub is safe. Dirty hot tub water is a matter of health, and it can even damage your hot tub over time. That’s because mineral deposits and black mold can form in your hot tub, and they’re hard to remove. 

It’s hard for mold spores to survive in your hot tub if you treat the water regularly. That’s especially true if you shock your hot tub with a high dose of chlorine once per week. However, you must adjust your water treatment routine based on how often you use your hot tub.

For example, it’s worth shocking the water with chlorine twice weekly if several people regularly use your hot tub. That’s because of the extra sweat and skin oils that will get in the water. Never get in a hot tub right away after you shock it, as the chlorine can irritate your skin, eyes, and lungs. 

3. Dirty Cover

It’s easy to neglect the cover when you deep clean your hot tub, but that’s a mistake. Hot water constantly condenses onto your hot tub’s cover, which leaves it damp most of the time. No light can get into your hot tub when the cover is on.

Condensation paired with darkness can create the perfect storm for black mold. Mold spores are hard to detect when they first form on the underside of a hot tub. However, their presence doesn’t matter as much if you regularly clean the cover with chemicals. 

You can even use a simple mixture of warm water and mild dish soap to keep your hot tub cover clean. Otherwise, you can clean the cover with products like Simple Green and Leisure Time Spa Cover Care & Conditioner. Thoroughly rinse the cover to remove the chemical residue when you’re done and put the cover back on your hot tub. 

Is Black Mold Dangerous In A Hot Tub?

Black mold is dangerous in a hot tub, so you must get rid of it right away. Exposure to black mold can cause respiratory problems, skin irritation, eye irritation, and fungal infections, among other complications. Some people are more sensitive to mold exposure than others, so it isn’t worth the risk of exposure.  

It’s best to avoid getting in the water even if you just see black mold on the inside of the cover. Mold spores are hard to detect, so they can spread throughout your hot tub even if you don’t see them. Check the filter for black mold after you treat the water and clean the cover.

Mold may linger in the filter, and that can cause problems even if you clean the water. Any remaining mold can taint the water and cause more spores to spread throughout your hot tub. It’s only safe to get back in your hot tub after you’ve cleaned it and made sure the filter is clear.

What Causes White Mold In Hot Tubs?

White mold is different than black mold in a hot tub, as it’s mostly caused by skin oils and dead skin cells. Don’t panic if you see white mold in your hot tub, as it’s more common than you may think. That’s especially true when you use your hot tub regularly over a short period of time without cleaning it.

The combination of oils, dead skin cells, and bacteria can contribute to white mold. Many people discover white mold in their hot tub when the water has been stagnant for a while. Luckily, you can often get rid of white mold in your hot tub within 1-3 days.

First, you must shock your hot tub with a high dose of chlorine and leave it uncovered for a while. Test the water to make sure it’s at 20 parts per million, as high doses are key to eradicating mold. Repeat this process for 1-3 days until the mold is gone. Wait to get in until the chlorine level is 3-5 parts per million. 

What Is The Slime In My Hot Tub?

The slime in your hot tub is most likely biofilm. Biofilm is the result of microorganisms and bacteria that build up within your hot tub. You may first find the biofilm resting on the seats, walls, and filter in your hot tub before it spreads.

As it grows, the biofilm may float in the water, and that’s an unsettling sight for anyone. Not only is it gross to look at, but biofilm can eventually damage your hot tub’s filter and plumbing. That’s because it will continually grow until it clogs the pipes. 

Luckily, you can remove biofilm from your hot tub with high doses of chlorine and biofilm cleaner. You can also run a hot tub plumbing cleaner through the pipes in your hot tub to remove the remaining biofilm. In extreme cases, you may need to replace your filter if it’s too clogged with biofilm. 

Summing It Up

The black mold in your hot tub is most likely because of stagnant water, condensation, and bacteria. Stagnant hot tub water can condense on the cover and cause mold to spread to the plumbing and filter. Treat the water with a high dose of chlorine to raise it to 20 parts per million to kill the mold and clean the cover thoroughly. 

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