Hot Tub Calcium Hardness

Hot Tub Calcium Hardness

The Hot Tub Calcium Hardness in your hot tub water is what keeps your PH Levels Balanced, But too Little or Too much calcium can cause problems quite quickly if not attended to.

Hot tub water does need some calcium to keep your PH levels balanced whilst using Alkaline control, but too much calcium can make the water cloudy and cause scaling on your spa’s parts and surfaces which can quickly cause problems with your hot tub internals.

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Signs Of Calcium build Up In a Hot Tub – What To Look Out For?

Look out for signs of scale deposits on your hot tub surfaces, Hot tub scale is the same as what you would see on your shower head or taps in your bathroom at home which is caused by hard water.

Another sign of “high or low” calcium levels in your hot tub water, is you will see froth on the surfaces of your water, It’s hard water that needs softening by using hot tub chemicals.

It’s very easy to spot calcium build-up, as your water looks seemingly bubblier/frothier on the surfaces of the water, especially whilst the jets are running.

Hot Tub Calcium Hardness – Recommended Calcium Levels

The ideal range for calcium hardness in an inflatable or acrylic hot tub is between 175 and 225 ppm (parts per million).

Do a simple test, Anything above or below this then you need to pay attention to your spa calcium levels low or high, and you should act immediately to avoid any damage to your hot tub.

To test for calcium hardness you can use a Test strip or Liquid Test kit.

You should test for calcium hardness about once a week to be on the safe side, especially if you haven’t added any new water to your hot tub recently whilst always keeping an eye on your water even if you’re not using the tub.

  • If you have hard tap water or are using the same water for a long period of time, you may need to test more often and shock your water more often for cleaner safer water.

There are four key factors that you need to keep track of regularly with your hot tub water.

  1. Sanitizer
  2. Calcium hardness
  3. Total Alkalinity Levels
  4. PH levels

This is particularly true for frequent users, as the high turnover of new fresh water added to your water dilutes the calcium naturally found in your spa water, causing calcium hardness to drop.

Low calcium levels can lead to very costly equipment damage and also reduce the lifetime of your hot tub.

Calcium Hardness In Your Hot Tub

We recommend testing your hot tub water for calcium hardness every week whilst adding fresh water frequently, although it may be more often if you’re using your spa heavily.

Calcium hardness is the amount of calcium present in your water.

While your water doesn’t need as much calcium as it needs chlorine or bromine, water does need some calcium to keep your pH levels balanced.

Top Tip – Keeping your PH levels and Alkaline levels correct will help reduce any calcium problems altogether.

But if you let those levels get too low or high, the water can deposit calcium on surfaces and equipment, including the heater and jets, Over time, this can cause serious damage to your spa if you don’t keep an eye on it.

Calcium hardness is the concentration of calcium dissolved in the water. It’s measured on parts per million (ppm) scale. The higher the number, the more calcium is present in your hot tub water.

If there isn’t enough calcium in your water, the water will start to pull it from the surrounding areas (such as your hot tub’s plumbing).

This process is known as “dissolution.” Once the plumbing has been compromised, you’ll start to see scale buildup and potential leaks.

  • Calcium is also what gives your water its hardness or softness.

Water with a high calcium hardness level is considered hard, while water with a low calcium hardness level is considered soft.

How To Test For Calcium Levels In Your Hot Tub

There are three different ways that you can test your water: Test strips, liquid test kits, and digital test meters that are not as accurate by experience.

A Test Strip – This is the most common way of testing for calcium levels in a hot tub. The test strip will change color depending on the amount of calcium in the water.

  • Simply dip the strip into your spa water and compare the color on the strip with the color chart on the bottle.
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Another way to check your spa’s calcium hardness level is a liquid test kit that checks for total hardness.

A Liquid Test Kit – This method involves a small glass tube, liquid reagent, and a clear plastic cover. A small amount of water is poured into the tube as directed.

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Then a few drops of liquid reagent are added and sealed with the plastic cover. After about 20 seconds, you match the color of the liquid to a chart on the bottle to determine calcium levels.

A Safe Range Of Calcium For A Hot Tub

Though the recommended level is between 175 ppm and 225 ppm, A safe range for total hardness is between 150 ppm (parts per million) and 250 ppm. Above or below this range then you need to take action to correct your water according to the recommended level.

If your total hardness is below 150 ppm, you should add a calcium hardness increaser to raise it back up to the recommended level.

If it is above 175 ppm, You should also add fresh water to dilute your current water and re-test.

Low Hot Tub Calcium Hardness Effect?

Corrosion – If your calcium levels are too low, (below 175 ppm), you’re at risk for corrosion and etching to your hot tub.

Corrosion begins when metals such as steel or copper start to break down due to chemical reactions with acids or other elements in the water.

You will see a white powder-looking material on shiny metal surfaces if you have high levels of calcium.

It’s easy for the water to become corrosive, which can cause skin rash and irritation to yourself if you have high levels and also cause damage to the hot tub itself as well as any metal parts inside of it and also cause

  • This includes things like pumps and heaters. metal corrosion to jets and other metal parts such as your hot tub’s ozone sanitizer.

the damage done to your spa’s equipment can be expensive to fix. Low levels of calcium hardness may also cause staining around the surface of your water.

Low calcium also causes etching on shiny acrylic surface finishes which in turn will make the surface of your hot tub look dull and feel less comfortable as the etched surface rubs on your skin as you move around.

  • It can also imbalance your water’s pH levels, and leach copper from your plumbing.
  • Etching occurs when surfaces are damaged due to low pH levels and/or low alkalinity levels.
  • Low calcium can also cause eye and skin irritation.

To fix this problem, you’ll need to add more calcium hardness increaser to the water until the calcium hardness level is back where it should be. simply add small amounts at a time and re-test every hour until to reach the correct hardness, always read the instructions!

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High Hot Tub Calcium Hardness Effect?

If your calcium levels are too high (above 175 ppm), you’ll notice scale forming on the interior surfaces of your spa.

  • You might see white flakes floating around or on the floor of your spa or a scaly residue on the sides of your hot tub.

Scaling is caused by minerals that precipitate out of solution and attach themselves to surfaces such as the walls of your hot tub, the hot tub pipes and equipment, and possibly even around the plumbing fittings.

  • This can clog filters and make the water cloudy and unpleasant to bathe in.

High calcium hardness is usually easily corrected by draining and replacing some of the water in your hot tub.

You can test calcium hardness yourself with test strips or liquid test kits.

You can also use a sequestering agent to remove the excess minerals so that they don’t build up in your water.

Using a total dissolved solid known as (a TDS reducer) will help as well by lowering the amount of minerals in the water.

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How To Increase Water Hardness – Hot Tub

  • To increase water hardness, Simply Add Calcium Chloride hardness increaser to the water.

How To Lower Hot Tub Calcium Hardness:

  • Drain all or some of your tub and refill with fresh, soft water.
  • Use an ion exchange product to lower water hardness.
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If your hot tub calcium hardness is below 175 ppm, (parts per million) you have very soft water, which can be very corrosive to hot tub equipment

If your calcium levels are above 225 ppm (parts per million) you have very hard water. Hard Water can cause scaling and staining on hot tub surfaces and it’s time to sort it out using the information we kindly provided for you on this page.

When your water has high or low calcium hardness levels you may see:

  • Etching or pitting of acrylic surfaces
  • Corrosion of metal parts such as jets
  • Dissolving of copper heater elements
  • Staining of surfaces where high pH causes scale precipitation
  • Calcium scale formation on the surfaces of plumbing components and heaters

Wrapping Up:

Now we have covered all there is to know about the ideal range for hot tub calcium hardness which is between 175 and 225 ppm (parts per million). and what measures you need to take to keep your calcium levels correct it’s time to wrap up.

Thanks For Reading…

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