Hard Water In Hot Tub: The Only Solution That Works


One of the most common concerns of every hot tub owner is hard water or having high levels of calcium in the water. Not only will this negatively impact your hot tub and its parts, but it will also have detrimental effects on your skin and hair, which is why learning how to soften hot tub water is an essential skill that every hot tub owner must learn. Dealing with hard water in the hot tub isn’t overly difficult, although it will require some work. But before we get started, let’s take a deeper look at what hard water is and the underlying cause behind it.

What is Hard Water?

As mentioned earlier, hard water is simply a term used to describe water that has high concentrations of naturally-occurring dissolved minerals. There will be various types of dissolved minerals that can be found in the water you put in your hot tub, but the most common of these is calcium (hence, the term “calcium hardness”). The opposite of hard water is soft water, which then happens when the calcium levels in your hot tub water are too low.

Hard water doesn’t have anything to do with the brand or model or your hot tub, so whether you have one of those high-end Coleman hot tubs or a traditional wood-fired hot tub doesn’t matter. Instead, water hardness is generally influenced by the water quality and conditions in your area, as well as the water treatment procedures employed by your water concessionaire.

As such, you need to test your hot tub water every time you fill your hot tub with fresh water and balance it accordingly if necessary. This is why aside from lowering chlorine and bromine levels in a hot tub, you also need to know how to soften hot tub water by lowering the calcium levels.

Hard Water and Your Hot Tub

Having hard water in a hot tub can have various negative effects on the hot tub and its different parts, preventing them from working properly or even causing them to fail. Some of these issues are outlined below.

  • When the hot tub is turned on and the water starts to heat up, the dissolved minerals in the water are further broken down. These then accumulate and build up to unsightly deposits or scales. Not only are they difficult to remove but will also cause clogging in the hot tub filter cartridges and plumbing lines of the hot tub. Over time, this buildup will cause your hot tub equipment to stop functioning properly and even damage them.
  • Cloudy Water. Another negative of high concentrations of calcium is cloudy water. The minerals start to accumulate and clump together which then leaves a residue on water thus making it look murky and cloudy.
  • Chemical Imbalance. When your calcium levels are off-balance, it can prevent other chemicals in your hot tub to disperse properly and mix well with the water. This is one of the primary reasons why you need to know how to soften hot tub water, otherwise, all the other hot tub sanitizers and other chemicals you put in the hot tub water will not work and adversely affect the water quality.
  • Inefficient Heat Transfer. Buildups and scale deposits brought about by hard water in a hot tub can prevent efficient heat transfer, which in turn will force your hot tub heater to work harder than necessary resulting in higher energy bills, premature failure of the heating element, and raise your overall hot tub running and maintenance cost.

Hard Water and Your Body


Hard water in a hot tub is not harmful to a person’s overall health, but it can have several negative effects on your skin and hair such as the ones mentioned below.

  • Skin Dryness. Some of the minerals found in hard water can remain on your skin after using your hot tub. These minerals can absorb much of the moisture and natural oils on your skin, thus causing it to dry up.
  • Clogged Pores. Many of the dissolved minerals found in hard water are so minute that they can easily enter the pores and clog them up. When this happens, dirt and oil trapped inside the pores cannot be cleaned and will, in turn, lead to messy acne breakouts.
  • Irritated Skin. Hard water has also been found to be a contributing factor to chronic skin conditions like eczema. Again, the high amounts of calcium in the water can rob the skin of moisture and other natural oils, not only causing it to dry up but also become irritated and itchy. If you are currently suffering from skin conditions like this, then knowing how to soften hot tub water is an essential skill you need to learn.
  • Dry, Frizzy Hair. Hard water in a hot tub can also be detrimental to your hair, especially if you let your hair soak in the water while you bathe. This is because hard water strips the hair of valuable moisture and oils which is necessary to keep it healthy and strong. When this happens, your hair becomes dry and frizzy and even prone to breakage.

You’ll also notice that it’s more difficult to rinse yourself with clean water after bathing in a hot tub with hard water. This is because some of the minerals can stick to your skin and form a sticky barrier or film which prevents the soap and water from thoroughly cleaning your skin. Some of the soap scum can also remain on the skin instead of being rinsed away, and because you are unable to properly wash it makes you prone to developing various skin problems.


Q: How do I lower the hardness in my hot tub?


To lower the hardness in your hot tub, follow the steps below:

  1. Get a calcium test kit and test your hot tub water for hardness. Get one test strip, soak it in the water and compare it with the color chart that comes with the kit. Accordingly, anything higher than 200 ppm (parts per million) is considered hard.
  2. If the calcium hardness is just above the recommended levels, you can go ahead to step 4. If the water is too hard, you’ll need to drain and clean your hot tub first before moving on to step 3.
  3. Fill the hot tub with fresh water. If you’re using a hose to fill the tub, remember to use a filter to reduce the amount of dissolved minerals that go into the hot tub.
  4. Add a calcium decreasing solution of your choice. Be sure to read the instructions because different brands have different recommendations.

5. Leave the solution in the water for at least two hours to let it mix with the rest of the hot tub water.

Q: Is Hard Water Bad for hot tubs?


Hard water in hot tub does have several negative effects on a hot tub and its parts. This includes scale deposits that form on the surface of the hot tub which can be very difficult to clean. Lime can also buildup inside the plumbing lines, cylinders, and hot tub filters which can then prevent them from functioning properly or even fail completely.

Globo Surf Overview

As a hot tub owner, one of the most common issues you’ll have to deal with is hard water in a hot tub. This is why you need to learn how to soften hot tub water to fend off the negative effects hard water can have on your hot tub and your skin and hair. Fortunately, this isn’t that difficult to do, and with a little care and maintenance, you should be able to keep the water in your hot tub in perfect condition and ready for every hot tub session.

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Globo Surf
My name is David Hamburg. I am an avid water sports fan who enjoys paddle boarding, surfing, scuba diving, and kite surfing. Anything with a board or chance I can get in the water I love! I am such a big fan I decided to start this website to review all my favorite products and some others. Hope you enjoy!