SpaBoss | Cal-Rise

SpaBoss Cal-Rise raises the calcium hardness of your hot tub water. It's a calcium chloride-based product used to bring soft water — typically from softened municipal taps or well water — up into the safe range for spa equipment.

Why calcium hardness matters in a hot tub: Water with too little calcium is "hungry" — it pulls calcium out of whatever it touches, including your heater element, salt cell, plumbing fittings, and any exposed metal in the spa. Soft water also foams more readily because there's nothing to neutralize the surfactants from soaps and oils. Bringing calcium hardness into the 150-200 ppm range protects your equipment and stabilizes water chemistry without pushing you into scale-formation territory.

When to use it: Test your calcium hardness with a drop test kit or a 6-in-1 test strip every time you fill the spa, and again monthly during normal use. If your reading is below 150 ppm — which is common in Waterloo Region municipal water and most of southwestern Ontario well water — add Cal-Rise to bring it up. Soft water that's been sitting in your spa for a few weeks will keep dropping calcium as it leaches it from your equipment, so retest after each top-off.

How to use it: With at least one pump running, sprinkle Cal-Rise slowly over the surface of the spa water. As a starting guideline, about 1 oz (30 g) per 1,000 litres raises calcium hardness by roughly 10 ppm. Wait 4-6 hours, retest, and add more if needed. Don't aim for the top of the range on day one — it's easier to add more later than to drain and dilute if you overshoot.

Quick tips:

• If you have an Onzen or Spa Boy salt water system, calcium hardness is non-negotiable — low calcium kills salt cells faster than anything else
• Always add calcium increaser separately from pH or alkalinity products; mixing them in the same dose can cause cloudiness
• If your water turns cloudy after dosing, run the jets and let it clear over 24 hours; cloudiness from calcium increaser is normal and self-resolves