How High Should a Hot Tub Be Filled?

Filling a hot tub is more than just adding water to the hot tub because the water has to be filled to the required level. So how high should a hot tub be filled? Here is the answer to that.

The water in the hot tub should be filled 3 inches above the filters and the jets. The filtration system of the hot tub is usually located on the side of the hot tub. The water needs to be at least 3 inches above the filtration system and the jets.

Some hot tubs also have a fill mark on the inner wall of the hot tub that indicates where the water should be filled before using the hot tub. But that’s not all. There is more to know about filling your hot tub correctly and this post digs right into the topic.

Let’s dive in.

Here we have explained how high should a hot tub be filled. This is an important thing to know because if you fill the hot tub too much then it can damage your filters and your jets.

Can You Put Too Much Water In A Hot Tub?

You can put too much water in a hot tub when you fill the hot tub above the required level. Hot tubs usually have a required level that the water should reach while filling the hot tub. If you fill the hot tub above this level, you will put too much water in the hot tub and this can damage the hot tub components.

So, can you put too much water in a hot tub? Here's what I found out.

When you put too much water in a hot tub, it leads to a hot tub overfill. This means the water inside the hot tub is too much for the hot tub to handle. Putting too much water in a hot tub can strain the hot tub components and lead to filtration problems.

Overfilling a hot tub will also damage the surrounding areas of the hot tub. When you get into a hot tub that has been overfilled, the water in the hot tub will spill over the sides and this can damage the base of the hot tub and cause etching.

This is because hot tub water is usually treated with lots of chemicals and sanitizers. The last thing you want is the water spilling on the hot tub base especially if the base or foundation was made out of concrete or wire mesh.

Putting too much water in the hot tub can also damage the electrical components of the hot tub that aren’t protected or insulated.

So always ensure to follow the instruction manual while filling the hot tub to avoid damages. But does a hot tub have to be full to turn on? Let’s find out.

Does A Hot Tub Have To Be Full To Turn On?

Hot tubs don’t have to be full to turn on. Your hot tub can be turned on regardless of if there is enough water in the hot tub or not. But turning on your hot tub while the water isn’t filled to the required level will damage your hot tub components.

Hot tubs require electricity to work. When the hot tub is plugged into the GFCI breaker and there is enough power, you can turn on the hot tub using the control panel. The jets and other hot tub components will also come on even if water isn’t enough in the hot tub. This is because the bot tub and the components are powered by electricity and not water.

Though hot tubs will come on even if the hot tub isn’t full, some hot tubs will go off after a while if there isn’t enough water in the hot tub. Many modern hot tubs usually have indicators that let you know when there isn’t enough water in the hot tub.

The indicator could be a code on the display screen or flashing lights on the control panel. If the hot tub is still running after the indicator has been on for a while, the hot tub will go off automatically to protect the hot tub components from being damaged due to lack of water.

So you should always ensure that the hot tub is filled to the required level before turning it on to prevent damages to the hot tub’s components.

Related Read: How Long Does It Take To Heat Hot Tub Water?

Do You Have To Continuously Add Water To Your Hot Tub?

You have to continuously add water to your hot tub at regular intervals even after you have filled the water to the required level. This is because hot tubs lose water through spills and evaporation. So to keep the water level at the required height, you will need to top up the water when the water level gets low.

You should add water continuously because hot tubs lose a lot of water due to evaporation and water splash.

Filling your hot tub with water isn’t a one-time task. Asides from the first time you put water in the hot tub, you will still need to continuously add water to the hot tub to help the hot tub cope with water loss.

Hot tubs lose about 1 inch of water every week under regular use and about 2 inches of water under heavy use due to evaporation.

The water in your hot tub is usually about 104 degrees Fahrenheit. Water at this temperature will produce a lot of steam which is water that is being evaporated into the atmosphere. The water is also kept at this temperature for a long time due to the effects of the jets and the insulated hot tub walls. This means that the water in the hot tub is constantly evaporating and this reduces the water in the hot tub.

Also, every time you go into the hot tub, the hot tub loses water through spills and splashes. The effects of evaporation and spills can cause excessive water loss. So you will need to continuously add water to the hot tub whenever you notice that the water level is getting lower than the required height (3 inches above the filters and jets).

Your hot tub could also lose water due to a hot tub water leak. Here’s a guide on how to find hot tub water leaks.

But can you only fill half of your hot tub and what happens if you only fill half of your hot tub with water? Let’s take a closer look.

Related Read: Does the Hot Tub Water Evaporate?

What Happens If You Only Fill Half Of Your Hot Tub With Water?

If you only fill half of your hot tub with water, the hot tub components will get damaged quickly because they will suck in dry air rather than water, and this can cause a hot tub airlock.

Here we explained what happens if you fill the hot tub halfway through?

The hot tub and its components are designed to work in a required volume of water. This doesn’t mean they won’t work without water but using them without the required level of water will cause them to get damaged quickly.

When you have insufficient water levels, the hot tub filtration system and the jets will be above the water level. The filtration system and the jets are usually positioned on the side of the hot tub to keep the water clean and in circulation. If you only fill half of the hot tub, then water wouldn’t get to these hot tub components and that could spell disaster.

The jets positioned in the higher parts of the hot tub wouldn’t get any water and this means the jets would suck in air. The air sucked in by the jets will become trapped in the hot tub pipes and prevent water from being circulated properly.

The hot tub circulation pump will also be overworked because the water in the hot tub isn’t enough. This can cause the pump to start sucking in air which can cause burnout that will destroy the pump.

Filling a hot tub halfway also means you wouldn’t be able to enjoy the hot tub. Since the water is low, you wouldn’t be able to fully enjoy the hydrotherapy and comfort that the hot tub provides.

So whatever you do, never fill a hot tub halfway. Asides from the hot tub components being damaged, the hot tub wouldn’t serve any purpose to you too.

Related Read: Can You Fill The Hot Tub With Hot Water?

How Do You Fill A Hot Tub Correctly?

To fill a hot tub correctly, you need to ensure that the hot tub is filled to the required level and with the right steps:

Unplug The Hot Tub

The first thing to do before putting water in the hot tub is to unplug the hot tub. You can also turn off the GFCI breaker to cut off electricity to the hot tub temporarily.

This is a safe option because filling your hot tub while the hot tub is plugged in can damage the electrical components of the hot tub. Doing this can also lead to electrocution.

Ensure The Hot Tub Is Clean

You should check if the hot tub is clean. The hot tub shell, filters, headrests, and jets should all be squeaky clean before you fill the hot tub. This prevents the introduction of dirt and grime into the hot tub water.

If any part of the hot tub is dirty, wipe them with a hot tub cleaning solution. Then rinse the hot tub.

Related Read: Can You Use Rainwater To Fill Your Hot Tub?

Attach A Pre-Filter To The Garden Hose

Most hot tub owners fill their hot tubs with a garden hose. You should attach a pre-filter or hose filter to the garden hose to filter debris and contaminants out of the water while filling the hot tub.

Connect one end of the hose to the tap. The other end should be inside the hot tub. You can also remove one of the filters and put the hose in the hot tub through the filter space.

Turn On The Tap And Wait

With the hose carefully fixed in the hot tub, you can turn on the tap. Ensure to keep tabs on the water level while filling the hot tub so you don’t overfill.

There might be a mark on the inner shell of the hot tub that indicates where the water should reach. If there isn’t any mark, you can check the hot tub manual or just fill the water 3 inches above the jets and filtration system.

Turn Off The Tap

When the water is filled to the required level, turn off the tap and disconnect the hose from the hot tub. The water cleanliness is high, but you still should treat the water with the right chemicals to ensure the water is safe for the bathers.

Final Words

Overall, filling your hot tub correctly isn’t difficult. All you have to do is know the required height that the water has to reach and then fill the water to that level.

If you ever overfill or underfill your hot tub, ensure to drain or top up the water before you use the hot tub.

So there you have it. If you liked this post, ensure to check out others like it on this website for more hot tub tips. Have a nice day.

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