1 level capful (2 level tablespoons) of this product will increase the calcium of a 500 gallon spa by approximately 10 ppm.

DIRECTIONS for use:

1. Determine amount of product to be added using a calcium hardness test kit.
2. Pour proper amount into spa or hot tub with equipment turned ON.
3. Run filter for 1-2 hours.
4. Water may be retested in 20 minutes.

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Brand Website Reviews

Customers on the AquaDoc site say the AquaDoc Calcium Increaser for Hot Tub Water is easy to use and helps support balanced calcium levels in spa water, with many noting it integrates smoothly into their regular hot tub care routine and helps protect surfaces from soft-water effects when added as directed.

Amazon Review Summary

On Amazon, the AquaDoc Spa Calcium Hardness Increaser listing shows positive product descriptions and customer interest in raising calcium hardness to prevent corrosion, etching, and staining, with buyers appreciating that a little goes a long way and instructions are straightforward (though specific star ratings are limited).

Walmart Review Summary

At Walmart, the AquaDoc Spa Calcium Hardness Increaser for Hot Tubs has earned customer reviews with about 4.5 ★ overall, with buyers saying it effectively increases calcium levels in softer water and helps improve overall spa water balance when used as part of routine maintenance.

Reddit Discussions

In Reddit and hot tub owner forums, spa enthusiasts discuss managing water balance, noting that using a calcium increaser like the AquaDoc Calcium Increaser can help avoid soft-water issues and support clearer, more stable water when combined with testing and other chemical adjustments.

How do I decrease calcium levels in my hot tub?

If calcium levels are slightly elevated, draining a portion of the water and replacing it with fresh water can help lower hardness levels. Test the water and repeat as needed. Using a stain and scale control product, such as AquaDoc’s Stain & Scale control, can help manage calcium levels as part of regular maintenance. If calcium levels are extremely high, a complete drain and refill may be recommended.

What if Calcium scale deposits have formed on my hot tub?

If scale buildup is already present, AquaDoc’s Spa Stain & Scale formula can help address existing scale and support prevention of future buildup when used as directed. Maintaining properly balanced calcium levels may help reduce issues related to overly hard or soft water.

Where is AquaDoc’s Calcium Increaser made?

Our product is made, packaged, and shipped from the USA.

Is this product compatible with Baquacil?

Yes, this calcium hardness increaser is compatible with Baquacil systems and is designed to support spa surfaces without interfering with your sanitizer when used as directed.