{"id":628,"date":"2021-09-12T20:43:04","date_gmt":"2021-09-12T20:43:04","guid":{"rendered":"https:\/\/hottubzone.com\/?p=628"},"modified":"2023-02-06T18:27:20","modified_gmt":"2023-02-06T18:27:20","slug":"hot-tub-soft-water","status":"publish","type":"post","link":"https:\/\/hottubzone.com\/hot-tub-soft-water\/","title":{"rendered":"Can You Fill a Hot Tub With Soft Water?"},"content":{"rendered":"\n

Soft water is great for bathing in and makes excellent drinking water, but is it ok to use in a hot tub?<\/p>\n\n\n\n

You should not fill a hot tub with soft water because the calcium hardness level is too low. Low calcium in a hot tub causes foaming and damage to the spa shell, as well as pitting in surrounding surfaces. Low calcium can cause the pH to become unbalanced, resulting in corrosion to the jets, plumbing, and heating.<\/strong><\/p>\n\n\n\n

If you live in a soft-water area, you might not have any choice but to fill with soft water. Fortunately, there are ways to treat low calcium hardness levels, which make it safe for your hot tub.<\/p>\n\n\n\n

What should the water hardness be in a hot tub?<\/h2>\n\n\n\n

Calcium hardness is the measure of how much calcium (lime) is dissolved in water. Soft water has low levels of calcium and other minerals such as magnesium.<\/p>\n\n\n\n

While the combined level of calcium and magnesium give us a reading of water’s total<\/em> hardness, only the calcium component is relevant in the water balance calculation for hot tubs.<\/p>\n\n\n\n

You’ll see resources online providing guidelines for both calcium<\/em> hardness and total<\/em> hardness. Because the magnesium level isn’t important, it’s fine to follow guidelines for calcium<\/em> hardness or total<\/em> hardness. <\/p>\n\n\n\n

Water’s total hardness is measured in parts per million (ppm). The total hardness of your hot tub water should be between 175 and 250 ppm.<\/strong><\/p>\n\n\n\n

While a hot tub can tolerate a total water hardness up to 400 ppm, do your best to keep it within the optimum range.<\/p>\n\n\n\n

What happens if water is too soft in a hot tub?<\/h2>\n\n\n\n

While soft water might feel great on your skin, it will hurt your hot tub. When the calcium levels fall below 175 ppm, the water becomes aggressive in its attempt to obtain the calcium it lacks.<\/p>\n\n\n\n

It starts to dissolve calcium from any surface that it comes into contact with, resulting in the following problems:<\/p>\n\n\n\n