--- product_id: 28372696 title: "Spaguard Spa Calcium Hardness Increaser - 12 oz" brand: "spaguard" price: "€ 22.74" currency: EUR in_stock: true reviews_count: 8 category: "Spa Guard" url: https://www.desertcart.hr/products/28372696-spaguard-spa-calcium-hardness-increaser-12-oz store_origin: HR region: Croatia --- # Compatible with all major sanitizers Boosts calcium hardness by 25 ppm/tbsp Prevents corrosion & etching Spaguard Spa Calcium Hardness Increaser - 12 oz **Brand:** spaguard **Price:** € 22.74 **Availability:** ✅ In Stock ## Summary > 🛁 Elevate your spa game—because your relaxation deserves the best! ## Quick Answers - **What is this?** Spaguard Spa Calcium Hardness Increaser - 12 oz by spaguard - **How much does it cost?** € 22.74 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/28372696-spaguard-spa-calcium-hardness-increaser-12-oz) ## Best For - spaguard enthusiasts ## Why This Product - Trusted spaguard brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Corrosion Defense:** Protect your spa’s plumbing, jets, and surfaces from costly damage caused by low calcium levels. - • **Effortless Integration:** Seamlessly works with chlorine, bromine, ozone, and biguanide sanitizers—no compatibility worries. - • **Trusted SpaGuard Quality:** Backed by thousands of 5-star reviews and industry-leading expertise for reliable spa care. - • **Precision Calcium Control:** Easily raise calcium hardness to the ideal 200-400 ppm range for spa longevity. - • **Balanced Water, Clear Experience:** Steady calcium increase without scale buildup or cloudy water—spa perfection guaranteed. ## Overview SpaGuard Spa Calcium Hardness Increaser is a granular formula designed to precisely boost calcium levels by 25 ppm per tablespoon per 100 gallons, maintaining the optimal 200-400 ppm range. This prevents corrosion and etching of spa equipment and surfaces, extending their lifespan. Compatible with all major sanitizers, it ensures balanced, clear water without scale buildup. Trusted by thousands, SpaGuard delivers professional-grade spa protection in a convenient 12 oz package. ## Description SpaGuards Calcium Hardness Increaser enables spa owners to increase their calcium hardness with this easy to use granular formula. This product will boost your calcium hardness. Low levels cause extensive corrosion of plumbing, jets, fixtures, and tub surfaces. Calcium Hardness Increaser will help raise the calcium level at a steady but not create scale build-up and cloudy water. The optimal calcium hardness level is 200-400 ppm, while anything below 100 ppm will cause corrosion. Raises calcium levels. 1 tbs. per 100 gallons increases calcium hardness-25ppm Prevents corrosion of equipment due to low calcium hardness Prevents etching of plaster due to low calcium hardness. When you use BioGuard spa care products (SpaGuard or Soft Soak), you are enlisting a group of individuals whose expertise is unsurpassed in the spa and pool industry. Whose dedication to helping you achieve perfect water no matter what the individual circumstance is their number one priority. Whose sole purpose is making your spa or pool the most enjoyable and trouble-free experience that you and your family will ever have. Whose dedication to the innovation and history of new product introductions is never matched, but often imitated. This dedication to service and the relentless pursuit of perfect water is inherent in the DNA of every BioGuard dealer. Review: Good product - Good price and product works well ! Review: Great product - This chemical line works great in my hot tub ## Features - Boosts Calcium Hardness: SpaGuard's Calcium Hardness Increaser enables spa owners to increase their calcium hardness with this easy to use granular formula, which will boost your calcium hardness to above the danger zone, where low levels cause extensive corrosion of plumbing, jets, fixtures, and tub surfaces. - Keeps Optimal Calcium Level: It helps raise the calcium level steadily to the optimal calcium hardness level of 200-400 ppm, to keep the spa water from becoming corrosive to heating elements and other equipment. - Protects Spa & Equipment for Longer Life: This helps protect your hot tub against corrosion, extending the life of your equipment and hot tub surfaces. - Compatibility: Calcium Hardness Increaser is compatible with chlorine, bromine, ozone and biguanide sanitizers. - Tested and Proven Effective: SpaGuard products are known for delivering reliable results and making spa care less complex. SpaGuard carries an extensive line of spa solutions that match your unique needs. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B007ZUD2IU | | Best Sellers Rank | #1,648 in Patio, Lawn & Garden ( See Top 100 in Patio, Lawn & Garden ) #13 in Swimming Pool Balancers | | Brand | SpaGuard | | Brand Name | SpaGuard | | Customer Reviews | 4.7 out of 5 stars 3,831 Reviews | | Item Form | Powder | | Item Weight | 12 Ounces | | Manufacturer | SpaGuard | | Manufacturer Part Number | 42257BIO | | Manufacturer Warranty Description | Returns are not accepted on opened or used items and are subject to a 20% restocking fee. | | Model Number | BIO42257 | | Number of Items | 1 | | Number of Packs | 1 | | Product Benefits | Prevents Corrosion | | UPC | 017541612326 017541646123 | | Unit Count | 12.0 Ounce | ## Product Details - **Brand:** SpaGuard - **Item Form:** Powder - **Item Weight:** 12 Ounces - **Product Benefits:** Prevents Corrosion - **UPC:** 017541612326 017541646123 ## Images ![Spaguard Spa Calcium Hardness Increaser - 12 oz - Image 1](https://m.media-amazon.com/images/I/613+hwIHJLS.jpg) ## Available Options This product comes in different **Size** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Good product *by E***S on March 17, 2026* Good price and product works well ! ### ⭐⭐⭐⭐⭐ Great product *by M***P on March 12, 2026* This chemical line works great in my hot tub ### ⭐⭐⭐⭐⭐ Works great *by W***D on April 28, 2026* Works great --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/28372696-spaguard-spa-calcium-hardness-increaser-12-oz](https://www.desertcart.hr/products/28372696-spaguard-spa-calcium-hardness-increaser-12-oz) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-06-25*