Adjusting the Hardness Level

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The hardness level is determined by the amount of calcium in your water. It’s more common to have a low hardness level versus a high one. Liquid Calcium allows you to raise your spa water 28 parts per million in a hot tub with 250 gallons with just 2 ounces. Double that to 4 ounces for a large 500-gallon hot tub, and triple to 8ounces for a swim spa.

The hardness level in hot tub water should be between 150 to 250 ppm.
An unacceptable hardness level can cause increased foaming, cloudy water, and if left uncorrected, it can cause damage to your spas equipment and even create scaling on your spa shell surface.

This chart gives you a simple guide for how many ounces to add depending upon your current hardness reading and the size of your spa.

Before adding, make sure your filtration pump is running, pour in an appropriate amount, wait 30 minutes, then retest. Add more if necessary.

Once you correct your hardness level, it is usually stays corrected until you drain and refill your spa. Adding over 8 ounces is ineffective in hot water and may take some time to take longer to correct the hardness level fully.

We recommend testing and correcting your hardness level when filling your spa when the water is still cold. You can add as much as you need to cold water to correct the imbalance.

There is no chemical available that can lower the hardness level in the water. The only corrective measures for that are to have water delivered, use water from a water softener if you have one, or purchase a portable water softener.

If you are unsure of the hardness reading on your 4-way test strip, there are test strips specifically for testing hardness levels.

Properly Testing Your Water