How to Adjust Water Hardness in Your Hot Tub

Keeping your water hardness levels in check is one of the easiest ways to make sure your hot tub feels great and lasts a long time. Too hard and you might see scale or cloudy water. Too soft and metal parts can corrode.

If you own a hot tub, knowing how to increase water hardness in your hot tub or lower water hardness in your hot tub is super helpful. In this post, we’ll explain what water hardness is, why it matters, and exactly how to adjust it so your water stays clear and comfortable.

What Is Water Hardness and Why It Matters

Water hardness is basically the amount of dissolved minerals in your spa water, mostly calcium and magnesium. Low hardness can make water corrosive. High hardness can cause scale, cloudy water, and reduce chemical effectiveness.

Keeping your water hardness levels between 200 and 400 ppm helps:

• Prevent scale and cloudy water

• Protect pumps, jets, and heaters

• Keep chemicals working properly

• Make your hot tub feel soft and nice

So it’s really worth checking your water regularly.

How to Increase Water Hardness in Your Hot Tub

If your water hardness levels are too low, a calcium hardness increaser for hot tub is the solution.

Adding Calcium Hardness Increaser

• Measure your hot tub’s water so you know how much to add.

• Dissolve the powder in a bucket of water first, so it doesn’t sink and settle.

• Pour it evenly around your spa. Turn the pump on to mix it.

• Wait at least six hours, then test your water hardness levels again.

Start small. It’s easier to add more later than fix too-high hardness.

How to Lower Water Hardness in Your Hot Tub

When your water hardness levels are too high, you can fix it with a simple water change or a hardness reducer.

Water Dilution

• Drain the spa completely.

• Clean the shell with hot tub cleaner.

• Refill with fresh water and test hardness.

• Repeat if needed until your water hardness levels are in range.
  
  

Using a Hardness Reducer

• Add a chemical hardness reducer according to instructions.

• Turn on the pump to mix it in.

• Chemical hardness reducers usually bind calcium to prevent scale rather than permanently removing it. A partial water change may still be needed for very high hardness.

• Test the water after several hours to make sure your water hardness levels are right.

Either way keeps your water clean and your hot tub safe.

Tips for Healthy Water Hardness

• Test your water at least once a week, or 2–3 times per week if your spa is used frequently or topped up often.

• Adjust in small steps.

• Follow package instructions for calcium hardness increaser for hot tub or hardness reducer.

• Regular maintenance prevents scale and corrosion.

• Keep notes on what you added and when.
  
  

Keep Your Hot Tub Balanced and Enjoyable

Managing your water hardness levels doesn’t have to be complicated. Knowing how to increase water hardness or lower water hardness in your hot tub keeps your water clear, protects equipment, and makes your spa more enjoyable.

With regular testing, small adjustments, and the right products, you can keep your hot tub water healthy, prevent scale, and soak in clean, soft water anytime.

Want to make hot tub care easier? Try TubTabs all-in-one chemical kits. They help balance water hardness levels, maintain pH, and keep your spa crystal clear without a lot of guesswork.