Do Hot Tubs Lose Water? (& How To Prevent it)

If you own a hot tub, then you will notice that the water levels drop often. Does that mean that the water is leaking, or do hot tubs lose water? I did some tests and here is what I found out.

Due to evaporation most of the hot tubs lose water. They lose about 1/2 inch every week. This is totally normal. But, there are a few things you can do to prevent that. 

If your water levels drop too much, then it could be a sign of leakage. Make sure to check that too. If that’s not the case, then check our tips.

Why Do Hot Tubs Lose Water?

Hot tubs lose water due to evaporation. It’s a natural thing that happens with pools, the sea, and other things. 

Evaporation is a process that makes your hot tub water change from a liquid to gas.  The gas goes into the atmosphere and then comes back into the earth from rain, ice, or snow.

While you can’t stop evaporation, you can minimize it, especially for your hot tub.

How Fast Does Hot Tub Water Evaporate?

Depending on the temperature, and how much water the hot tub has, it can lose up to 2-inches of water per week from evaporating. You can still lose 1-inch of water from water spilling.

If the temperature is hot, then you might lose more water. If your hot tub is filled full, then you will lose less water. All these factors determine how much water is evaporating from your hot tub.

But, the normal rate of evaporating is 2-inches of water per week. If you notice that you are losing more than that, then your hot tub might be leaking water.

How Long Does It Take For Hot Tub Water to Evaporate?

There are a few factors that determine how fast your hot tub loses water. While most hot tubs lose 1 or 1/2-inch of water per week, it still depends on a lot of factors.

Volume Water

The more water your hot tub has, the less the loss will be. The reason for that is because if there’s a lot of water, then it will take longer for the heat to get through the top layers. Once the heat goes through the top layers, then the molecules start to evaporate.

Hot Tub Size

The larger the water surface area the faster your water will evaporate. If you take your hot tub water and put it on a football field, then it will evaporate even faster. Why? Because the heat can go through top layers faster because there’s a low water depth.

Hot Tub Water Temperature

The hotter the hot tub water is, the faster is going to evaporate. Once the water reaches a boiling point, it will produce steam very quickly. The hotter the water is, the closer the evaporate point is. Hot tubs with cold water tend to lose less water than hot tubs with warm water.

Related Read>>> Are Inflatable Hot Tubs Good in Winter?

How to Prevent Hot Tubs From Losing Water?

The evaporate process isn’t a big deal. Typically, you will lose about a 1-inch per week from that process. You can easily replace that. But, if you want to minimize a hot tub from losing water, here are some tips:

You can't stop the evaporation process. But, you can minimize it. So, how to prevent hot tubs from losing water? Use a hot tub cover, use a lower water temperature, and protect your hot tub from the sun.

1. Use a Hot Tub Cover

A hot tub cover will definitely help you lose less water. The cover minimizes the heat that reaches your water and therefore minimizes the evaporating too.  A hot tub cover is good for other things too. It protects your hot tub water from dirt and different pests. Plus, keeps your water warmer in the winter.

2. Protect Your Hot Tub

If your hot tub is outside, and there’s sunny weather, then you will lose water faster. You can get a gazebo for your hot tub. That will minimize the water loss, plus it makes the hot tub look better. If you are using an inflatable hot tub then you can try to place it in your garage while you are not using it.

3. Reduce The Water Temperature

We learned above that the higher the water temperature is, the faster you will lose water. To minimize that, you can try to reduce the temperature. Personally, I wouldn’t do this. I’m using the hot tub for the hot water. But, if you want to minimize the water loss then you should do this.

Related Read>>> Can You Use Hot Tubs With Cold Water?

Can You Add Water to a Hot Tub?

Yes, you should add water to your hot tub every week or two. Use a hose (with a hose filter) and start to fill the hot tub until it reaches desired level. Make sure to test the water chemistry once you are done.

Adding water to a hot is recommended. Most of the dirty water goes away from evaporating, so adding fresh water will make your hot tub cleaner.

While adding water with a hose make sure to use a hose filter. The hose filters prevent unnecessary molecules and chemicals (such as iron) to reach your hot tub water.

After you add the water, you should check the water balance. Take a test strip and check your pH levels and alkalinity. The pH levels should be 7, while the alkalinity should be between 100-150 ppm.

How to Know if My Hot Tub is Evaporating or Leaking?

If you are losing too much water, then your hot tub could be leaking rather than evaporating. Here are a few things you should check:

If you see water around your hot tub you will not know if your hot tub is leaking or evaporating. That's why we have explained how to know if my hot tub is evaporating or leaking.

Check The Water Drop Levels

The first thing you need to do is to know how much water you are losing. If you are losing 1-inch or 2-inches of water per week, then that’s your water evaporating, and that’s normal. You can use the tips above to minimize that, but that’s nothing to worry about.

If you find that you are losing more than 2-inches of water per week, then you should check if your hot tub is leaking.

Related Read: How High Should You Fill Your Hot Tub?

Is There Water Around Your Hot Tub Cabinets?

If your hot tub is evaporating then there won’t be water around the cabinets (from the process). Check the cabinets and see if there’s water. You should check the cabinets and surroundings only when it’s clear weather. If it’s rainy, then you can’t know for sure.

Also, having a concrete base will help you see clearly. A wooden deck can soak the water. If you find water that means your hot tub is leaking. Try to locate where the water is coming from. And fix that.

Check Your Pump

The pump deals with a lot of water. The pump also vibrates a lot, and it can easily leak water. Check underneath the pump and see if there are any water drops. If you find a lot of water underneath the pump, then you need to replace the pump.

If you see only a few drops, take a cloth and clean the surface. Go and check it again after a few days.  If you see more water drops then your pump is leaking the water. If you don’t see water drops then it’s not the pump fault.

If you still think that your hot tub is leaking water, then check the hot tub base and the other hot tub parts. If you checked all, and still losing a lot of water, then it’s best to call an expert.

Related Read>>> How To Find a Leak in Inflatable Hot Tubs?


If your hot tub water is evaporating, you shouldn’t worry. It’s a normal thing. You can try to minimize it with our tips, but why do that? Once you see your hot tub water drop, you can just fill it with clear water.

But, if for some reason you want to minimize that, then using a hot tub cover, and using a low temperature will help you lose less water.

Recent Posts