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SpaGuard Calcium Hardness Increaser | Spa Balancer

SKU: 42636BIO
$7.99

In stock

Pickup available at Leisure Time Inc. - Idaho Falls

Usually ready in 24 hours

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Description

SpaGuard Calcium Hardness Increaser raises the calcium hardness level in spa and hot tub water. It's an easy fix for one of the most overlooked balance problems in spa care: water that's too soft. When calcium runs low, the water turns aggressive and starts looking for minerals to dissolve — pulling them out of your equipment and surfaces instead.

Low-calcium water causes three real problems. It corrodes metal components like the heater and fittings, it can etch and damage spa surfaces, and it tends to foam. Maintaining a proper calcium hardness level protects your spa from all three. Calcium is one of the three core balance numbers — alongside pH and total alkalinity — and keeping it in range is part of water that's gentle on both your spa and the people in it.

This granular formula dissolves into the water to bring soft water back up to a protective level, and it works with every common sanitizing system.

Pro Tip: If you've refilled with soft or filtered water and you're battling stubborn foam that defoamer only fixes temporarily, check your calcium hardness before reaching for more chemicals. Low calcium is a frequent hidden cause of foaming — and raising hardness solves it at the source.

Brand

SpaGuard®

What's in the Box
  • 1 x SpaGuard Calcium Hardness Increaser — 12 oz. (resealable bottle, granular)

Note: This product raises calcium hardness. If your hardness is too high (scale, cloudy water, crusty deposits), that's the opposite problem and calls for a different approach. Keep the bottle tightly sealed and store it in a cool, dry place away from other chemicals.

Key Features
  • Raises calcium hardness — corrects soft, low-calcium water and brings it into the protective range.
  • Prevents equipment corrosion — protects the heater, pump components, and metal fittings that aggressive low-calcium water attacks.
  • Protects spa surfaces — guards against the etching and damage caused by calcium-starved water.
  • Reduces foaming — low calcium is a common cause of persistent foam; raising hardness addresses it at the source.
  • Granular, no pre-dissolving — broadcast it straight into the water with the circulation system running.
  • Works with every common sanitizing system — chlorine, bromine, ozone, and biguanide.
How It Works

Calcium hardness is a measure of how much dissolved calcium is in your water. Water naturally "wants" to be saturated with minerals, so when calcium is too low, the water becomes aggressive and corrosive — it dissolves calcium from wherever it can find it, including your spa's surfaces and the metal in your equipment. That same soft water also struggles to hold its surface tension, which is why low calcium so often shows up as foam.

SpaGuard Calcium Hardness Increaser is a calcium-based granular product. Broadcast into circulating water, it dissolves and raises the hardness level so the water is balanced and protective rather than hungry and corrosive. The goal isn't maximum calcium — it's the right range. Too little is corrosive and foamy; too much leads to scale and cloudiness. This product is how you bring a low reading back up to that protective middle.

Pro Tip: Add in stages and retest. Calcium hardness doesn't drift down on its own the way pH does, so it's easy to overshoot and end up with scale-forming water that's hard to bring back without a partial drain. Sneak up on your target rather than dosing it all at once.

Directions for Use
  1. Apply the appropriate amount per ALEX Pro recommendations (or your water-test guidance). Broadcast into the spa with the circulation system operating.
  2. Do not pre-dissolve the product.
  3. Brush up any granules that do not immediately dissolve.
  4. Operate the circulation system for 30 minutes after application, then retest.

Pro Tip: Aim for a calcium hardness of 150–250 ppm for most spas. A SpaGuard dealer water test (using ALEX) takes the guesswork out of exactly how much to add for your spa's volume and current reading.

Specifications
  • Product: SpaGuard Calcium Hardness Increaser — Spa Water Balancer
  • Brand: SpaGuard (BioGuard family)
  • SKU: 42636BIO
  • Size: 12 oz.
  • Form: Granular — do not pre-dissolve
  • Function: Raises calcium hardness
  • Active Ingredient: Calcium Chloride (per manufacturer)
  • Application: As needed when calcium hardness is low
  • Method: Broadcast across the water with the circulation system running; brush up undissolved granules; circulate 30 minutes and retest
  • Target Calcium Hardness: 150–250 ppm (most spas)
  • Protects Against: Equipment corrosion, surface etching, and foaming from low calcium
  • Sanitizer Compatibility: Chlorine, bromine, ozone, and biguanide
  • Surface Compatibility: Safe for all common spa surfaces
  • Country of Origin: Made in USA
  • Shipping: Ships UPS Ground only
  • Hazmat Classification: Non-hazardous (calcium chloride); not a DOT-regulated chemical
Compatibility

Calcium Hardness Increaser is a water balancer that works with whatever sanitizing system you use:

  • Chlorine spas — fully compatible.
  • Bromine spas — fully compatible.
  • Ozone systems — compatible as part of a balanced-water routine.
  • Biguanide systems — compatible.
  • All spa surfaces — safe for use with all common spa surfaces.

Important: Calcium Hardness Increaser is a balancer, not a sanitizer. It corrects water chemistry but doesn't sanitize — use it alongside your regular sanitizer and shock.

Most products purchased from our online shop within the last 30 days are eligible for return. Please review our return policy to see the list of items that cannot be returned.

Some major items that are non-returnable:

  • Gift cards
  • Electronics
  • Pumps / Motors
  • Hot Tubs
  • Closeouts
  • Fireplaces
  • Electric Fireplaces
  • Massage Chairs
  • See return policy below for full list of non-returnables.

SpaGuard® Brand FAQs

What is SpaGuard?

SpaGuard is a professional-grade brand of spa and hot tub water care products — sanitizers, shocks, balancers, and water enhancers — formulated specifically for spas rather than adapted from pool chemicals. The line is designed to work together as a complete system for clean, clear, comfortable water.

Who makes SpaGuard?

SpaGuard is part of the BioGuard family of water care brands, a long-established name in pool and spa chemistry. That backing means the formulas are professionally developed and tested, with a reputation built over decades in the industry.

What water care systems does SpaGuard offer?

SpaGuard supports three complete care methods: a chlorine system, a bromine system, and the Soft Soak TRIO system. Each is a coordinated set of products, so you can match your routine to the sanitizer you prefer.

What makes SpaGuard different from generic spa chemicals?

SpaGuard products are engineered for the unique demands of hot, agitated, heavily used spa water, and they're built to work together as a system. That coordination delivers more reliable, repeatable results than mixing unrelated single products.

What is ALEX water testing?

ALEX is SpaGuard's exclusive computerized water-analysis tool used by its dealers. A quick water sample produces a precise read on your spa's chemistry and a tailored recommendation, taking the guesswork out of what to add and when.

Why buy SpaGuard from an authorized dealer?

SpaGuard dealers are trained on the brand's products and water-care technology, so you get expert advice alongside genuine product. They can run an ALEX analysis, troubleshoot issues, and recommend exactly what your water needs.

About SpaGuard®

SpaGuard is a professional-grade line of spa and hot tub water care products engineered specifically for spas — not pool chemicals repackaged for a smaller tub. Built around a simple, proven approach (balance the water, sanitize it, shock it, and keep it clear), SpaGuard products are formulated to work together as a system across three care methods: chlorine, bromine, and the Soft Soak TRIO system.

Because the formulas are made for the unique demands of hot, agitated, heavily used spa water, owners get reliable, repeatable results with less guesswork. SpaGuard is also backed by a trained dealer network and ALEX water-analysis tools, so when a water issue does come up, there's an expert-tested path to fixing it. It's a trusted choice for anyone who wants clean, comfortable, sparkling water with a maintenance routine they can actually keep up with.