6 Easy Steps to Control Hard Water

6 Easy Steps to Control Hard Water

Calcium scale in your hot tub can be unsightly: a chalky white film, dry flakey spots, or rough texture on surfaces. But it’s actually the scale you can’t see that’s more troublesome and costly. 

(Be sure you know that the cause of your scale is high calcium because it can also be caused by high alkalinity, body oils and other contaminants, or too many dissolved solids in your water. The best way to be sure is to test your water yourself or at your nearest hot tub retailer. When you have hard water, it becomes even more important to keep your water balanced as high pH leads to a reduced capacity to hold those minerals suspended in the water.)

When water is too hard, minerals will come out of suspension and be deposited on surfaces, leaving that white chalkiness behind. This residue occurs more easily in hot water — and the water is hottest in your pumps and heater, where build-up will reduce efficiency and eventually cause damage. Hot tubs are especially susceptible to scaling and hard water because as the water evaporates, it leaves the minerals behind (creating even harder water). Be aware: it is important to take care of hard water to prevent costly damage — and if you are noticing scale, you need to take action now!

The great news is that solving a hard water problem won’t just keep your hot tub working longer; it will make maintenance easier. Other symptoms of hard-water include water cloudiness and foaming. Solving your hard water problem may also mean using less sanitizer and having less “finicky” water.

Dealing with hard water can be simple if you know what to do. Here are the best five tips for dealing with hard water:

1. Add freshwater

There is no way to remove calcium and other minerals from your hot tub, but adding freshwater can lower hardness. Obviously, if your source-water is hard, that may not be easy. If you have a soft water system, you can drain some water from your hot tub and add softened water (but be careful not to make your hot tub water too soft as this will lead to minerals being pulled out of your hot tub components and equipment). If you do not have a water softener, you can use a pre-filter.

2. Use a pre-filter

hot tub pre-filter is a garden hose attachment that will remove hardness from water using ion-exchange resins. This method produces softer water from your source water during fill-ups and top-offs. The First Step Clean-N-Fill uses a 5-stage filtration process to both purify and soften source water. The bonus is that the filtration process will also lead to more straightforward water chemistry maintenance (think of it like using a Brita to fill your hot tub — but without so many trips to the facet).

3. Use a stain & scale protector

Depending on your water, a pre-filter may not be enough to lower your water hardness below the recommended 250 parts per million (though it will also decrease your total dissolved solids, further reducing the occurrence of scale). If your water is still too hard, you should add a stain and scale protector to your regular maintenance (just add a capful each week).

4. Replace your water “frequently”

As water evaporates from your hot tub, the remaining water becomes harder — after all, the water is leaving, but the minerals are staying. As you top off your water, you are adding more minerals. It is not long before your water becomes harder. If you have hard water, you should aim to change your water quarterly.

5. Clean your hot tub between water changes

When you empty your hot tub, be sure to clean all the surfaces to remove any scale that has built up. Be sure to flush your lines with clean water, too, so that you start with the freshest possible water (and don’t forget that pre-filter!).

6. Keep your water chemistry balanced

High alkalinity and high pH will reduce your water’s ability to hold minerals in suspension, causing them to build-up on the surface of your hot tub and inside the equipment. Be sure to check your water balance once a week and solve any water chemistry problems as they arise.


Managing hard water does not have to be complicated or take a lot of time. By pre-filtering your water, diligently testing your water, adding a protector, and replacing your water quarterly, you can make maintenance much easier (and protect your hot tub!).

Fast FREE Shipping

on all orders $49+

Huge Inventory

on popular hot tub products

Great Customer Service

call or chat with our dedicated team
American Express Mastercard PayPal Shop Pay Visa