Top 9 Calcium Hardness Increaser for Hot Tub – Kitchen & Dining Features

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1. SpaGuard


SpaGuard Spa Calcium Hardness Increaser, 12 Ounce

SpaGuard #ad - Prevents corrosion of equipment due to low calcium hardness. Per 100 gallons raises calcium hardness 25ppm. Prevents etching of plaster due to low calcium hardness. 1 tbs.
BrandSpaGuard #ad
ManufacturerSpaGuard #ad
Weight0.75 Pounds
Part Number42257BIO
WarrantyReturns are not accepted on opened or used items and are subject to a 20% restocking fee.



Leisure Time CB Calcium Booster Balancer for Spas and Hot Tubs, 32 fl oz

LEISURE TIME #ad - Features: prevents corrosion and foam; Part of Leisure Time's Simple Spa Care program. One ounce increases hardness 7 ppm in 500 gallons of water. Compatible with chlorine, bromine, ozone and biguanide sanitizers. Use: one ounce increases hardness 7 ppm in 500 gallons of water. Includes: one 32-oz bottle of Leisure Time Calcium Booster. Benefits: raises water hardness to maintain a level of hardness between 150-400 ppm. Compatibility: Compatible with chlorine, bromine, ozone, and biguanide sanitizers. Prevents corrosion.
ManufacturerLeisure Time #ad
Height9.5 Inches
Length3.12 Inches
Weight2.58 Pounds
Width3.12 Inches
Part NumberCB

3. Clorox


Clorox Pool&Spa 12204CLX Calcium Hardness Increaser, White, 4 lb

Clorox #ad - Ideal for plaster pools and soft water areas. Power source Type: Manual. Increases low Total Hardness levels in swimming pool water. For best results, use with the Clorox Pool app. Prevents corrosion, etching, and staining. Prevents pool surface damage.
BrandClorox #ad
ManufacturerClorox® Pool&Spa™ #ad
Height11.5 Inches
Length4.4 Inches
Weight4 Pounds
Width10 Inches
Part Number12204CLX

4. Spa Essentials


12-Ounce, Spa Essentials 32534000 Calcium Hardness Increaser Granules for Spas and Hot Tubs

Spa Essentials #ad - Helps prevent corrosion Of Spa Equipment And Surfaces. Easy to Use. Increases calcium Hardness Level In Spa Water. No assembly Required.
BrandSpa Essentials #ad
ManufacturerRobelle Industries #ad
Height8 Inches
Length3 Inches
Weight0.75 Pounds
Width3 Inches
Part Number32534000
WarrantyReturns are not accepted on opened or used products and are subject to a 20% restocking fee

5. Baqua Spa


14 fl oz, BAQUA Spa 88825 Calcium Hardness Increaser Spa and Hot Tub Balancer

Baqua Spa #ad - Compatibility: Works with all biguanide sanitizer systems. Includes: one 14-oz container of BAQUA Spa Calcium Hardness Increaser. Benefits: raises spa water to the recommended level of calcium hardness. Features: Bromine and chlorine free. Use: part of baqua spa's bromine-free and chlorine-free maintenance product line.
BrandBaqua Spa #ad
ManufacturerInnovative Water Care #ad
Height2.44 Inches
Length2.44 Inches
Weight1 Pounds
Width6.2 Inches
Part Number88825

6. Hot Tub Things


Prevent Corrosion in Your Spa, Hot Tub Things Calcium Increaser 32 Ounce

Hot Tub Things #ad - America's #1 trusted Brand of Hot Tub Chemicals. Add a little calcium increaser regularly to protect your hot tub from corrosion caused by low calcium. Compare to Leisure Time Calcium Booster. Formulated exclusively for Hot Tubs And Made from the Purest Chemicals Available. Safety tested to Assure Quality, Guaranteed Performance.
BrandHot Tub Things #ad
ManufacturerHot Tub Things #ad
Height9 Inches
Length3 Inches
Weight2.1 Pounds
Width3 Inches
Part Number850511004222

7. PureSpa


SpaPure Calcium Hardness Increaser 16oz

PureSpa #ad - Ensure water won't become corrosive. Fast acting liquid calcium hardness balancer. Protect your spa equipment and bather comfort.
BrandPureSpa #ad
ManufacturerHaviland #ad
Part NumberSPA2729CS20B6

8. SpaChoice


14-Ounces, SpaChoice 472-3-5031 Increase Calcium for Spas and Hot Tubs

SpaChoice #ad - Increases calcium Hardness in Spa Water. Downloadable user guide Available Under Product Information: Technical Specifications. The ideal hardness level is 200-400 ppm. Per 500 gallons to increase hardness by 10 ppm. Use a test kit or test strip to test your spa calcium levels. Use 1 oz. Low hardness will etch plaster and corrode spa equipment.
BrandSpaChoice #ad
ManufacturerRobelle Industries #ad
Height10 Inches
Length6 Inches
Width3 Inches
Part Number472-3-5031

9. Natural Chemistry


Natural Chemistry Spa Calcium Hardness Increaser 1.83 lb 2 Pack

Natural Chemistry #ad - Boosts the calcium hardness level in your spa or hot tub. Reduces eye and skin irritation. Prevents corrosion damage to spa surfaces, plumbing, and other equipment. 2 pack.
BrandNatural Chemistry #ad
ManufacturerNatural Chemistry #ad