How to Treat Hard Pool Water?- Step-by-Step Process

How to Treat Hard Pool WaterThe least things can replace the pleasure of swimming on a hot, summer day. It’s a great place to rejuvenate with your family. Since you are reading this, you may have observed something unusual on your pool surface.

You need to know about how to treat hard pool water, luckily we are going to answer this!

Now, let’s see what’s there for you!

What does hard water mean?

When there is a high range of calcium and magnesium in the water, it is called hard water.

Yes, calcium is good for your bones and teeth. But it’s not always good for the expensive Swimming pool equipment you bought to keep the pool clean and healthy.

In the long run, calcium hardness can really do some real damage. You will pay more for it. So, it’s high time to monitor and balance the calcium hardness in your pool.

What’s the right calcium hardness level?

Calcium is good for your pool until it crosses its limit. The acceptable ranges depend on some factors.

For a pool with the vinyl of fiberglass liner, calcium hardness should be between 175-225 ppm (parts per million).

In case you have a concrete or plaster pool, this range should be between 200-275 ppm.

If your pool water is too hard or too soft, you will be in trouble. So, the key thing is to keep it balanced.

What will happen if the water is too hard?

The higher the calcium hardness is, the harder the water will be. The first sign of hard water is cloudy pool water.

There are ways to clear your cloudy pool water.

But, if you follow the procedure a couple of times but the cloudiness doesn’t dissipate, it could be too much calcium in the water.

How to treat that hard water?

We will cover all the steps you need to go through.

1. Chip-off any calcium deposits

Before adjusting the calcium level of your pool, vacuum your pool to chip away any large calcium deposit on tile or plaster.

2. Drain and replace a portion of water

Find the areas with extremely high calcium and drain a portion of the water. Now, use a hose filter to keep out some of the minerals.

Keep draining the water until it’s about 4-6 inches lower than the original height. But in case you have a pool with a deep end you should remove 1-2 inches more.

Don’t ever drain all the water of your pool unless you have plans for structural adjustments. Otherwise, it can cause the pool to lift from its foundation as a result of a loss of weight.

3. Test the water for hardness

After testing replacing the water, wait for about 12 hours. Now, collect a calcium hardness test kit.

Take the test strip firstly, dip it approximately 18 inches below the pool water surface. Now, remove the strip and wait some time.

After a few moments, the color will change and indicate the hardness level. Compare the results you got to the ideal levels (as we said earlier).

4. Add a commercial hardness reducer

For softening the water to ideal levels, measure the recommended product and pour it into a clean bucket. Turn the pool pump on and broadcast the treatment around your pool slowly.

Keep the pump running for the next 24 hours. After five days of the treatment, add soda ash or borax to increase pH from 7.8 to 8.2.

Hence, we prioritize borax because soda ash tends to raise the TA.

5. Check the hardness level after 7days

Re-test the hardness level after 7days of the treatment. During this period, the minerals will bind with the chemicals and form larger molecules that will be flushed out of your pool through the filter.

How to get the perfect water hardness?

If you can totally avoid the high-level of calcium hardness, it would be best for your pool. For this, follow these instructions:

1. Maintain properly

Proper maintenance required cleaning, shocking, filtration properly for your pool water. Don’t neglect them, know first how to maintain your pool and keep it neat and clean.

2. Keep the water chemistry balanced

Keep your eyes open on the chemical balance of your pool water. It will help you to prevent the problems related to calcium hardness and so on.

Shock your pool regularly and test the water to keep the chemical balance perfect.

3. Test your water frequently

In case your water source is hard, this point is the most important for you. Testing pool water once a week is the best option. But at least once in two weeks is mandatory.

Make sure you are choosing a test strip that includes calcium hardness or takes a liquid test strip.

4. Notice the problems early

Don’t wait to make your pool disastrous by calcium hardness, if a single sign you can notice, take actionable steps as soon as possible.

Check the pH, total alkalinity of your pool water regularly. If one of them isn’t in the perfect range, you should be worried and solve it.

The dirt and debris make your pool water worse, so make sure you are cleaning them regularly. Take every problem seriously, it will make your path clear in the long run.

Remember, the later you will notice the problems, the bigger they will be and the more time they will require.


The end! You are done with treating the hard pool water. It’s really not an uphill battle to treat the calcium hardness.

Be careful from the beginning. We have shown you everything you should do about how to treat hard pool water. So, it’s not still a big question for you, right?

So, now you can lower the calcium hardness of your pool water if all the steps you follow are followed properly.

Be careful when you work with chemical and electrical devices and keep your pool clean. The smaller steps will help you to get a healthy, happy Swimming.

Happy treating!

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