--- product_id: 690229473 title: "52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (4 Pack)" brand: "hth" price: "€ 96.43" currency: EUR in_stock: true category: "Hth" url: https://www.desertcart.hr/products/690229473-52039-swimming-pool-care-shock-ultra-swimming-pool-chemical-cal store_origin: HR region: Croatia --- # Fast-acting Cal Hypo formula Compatible with all pool types Visible Blue Action indicator 52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (4 Pack) **Brand:** hth **Price:** € 96.43 **Availability:** βœ… In Stock ## Summary > πŸ”΅ Shock your pool, not your schedule β€” brilliance guaranteed! ## Quick Answers - **What is this?** 52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (4 Pack) by hth - **How much does it cost?** € 96.43 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/690229473-52039-swimming-pool-care-shock-ultra-swimming-pool-chemical-cal) ## Best For - hth enthusiasts ## Why This Product - Trusted hth brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **No Chlorine Lock:** Cal Hypo formula avoids cyanuric acid buildup for unstoppable sanitation. - β€’ **Skin & Eye Friendly:** Reduces irritation so your swim feels as good as it looks. - β€’ **Smart Weekly Routine:** Use with HTH 6-Way Test Strips to conquer 90% of pool problems effortlessly. - β€’ **24-Hour Crystal Clarity:** Shock your pool to sparkling perfection in just one day. - β€’ **Universal Pool Compatibility:** Safe for vinyl liners, saltwater, and all pool surfaces. ## Overview HTH 52039 Shock Ultra is a powerful, fast-dissolving Cal Hypo pool sanitizer that boosts chlorine levels without adding cyanuric acid, preventing chlorine lock and algae growth. Designed for all pool types, it kills bacteria, controls algae, prevents stains and scale, and reduces skin and eye irritation. The built-in Visible Blue Action confirms it's working, delivering crystal-clear water within 24 hours when used weekly as part of a smart pool care routine. ## Description The amazing all-in-1 weekly formula in HTH Shock Ultra increases chlorine levels, kills and prevents bacteria and algae, reduces eye and skin irritation, prevents stains from metals, prevents scale, improves filtration and softens waterβ€”all with results in 24 hours! Traditional chlorine products contain cyanuric acid (CYA). When too much CYA builds up, it can cause overstabilization or chlorine lock, cloud your water and cause algae growth. The fast-acting, fast-dissolving Cal Hypo based formula in HTH Shock Ultra provides chlorination without adding extra CYA for a beautiful sparkle all season. It’s ideal for all pool surfaces and won't fade your liner. How To Use: Follow the on-pack instructions according to your pool size to add HTH Shock Ultra directly to swimming pool water or skimmer. The built-in Visible Blue Action lets you know it’s working! For best results, apply HTH Shock Ultra as part of your weekly pool care routine to keep free available chlorine levels between 1 and 4ppm. About HTH Pool Care: HTH was developed with the pool owner in mind. We know that maintaining your pool water can be a lot of work. That’s why we're here every step of the way, helping you clear the uncertainty from pool care. With economical, easy-to-use solutions, HTH is designed to work hard so you're prepared to tackle whatever life throws in your pool. From balancing your water to treating green water, we offer a full line of pro ## Features - The information below is per-pack only - BENEFIT: Use this all-in-one powerhouse pool shock to increase chlorine levels, prevent bacteria, algae, stain, and scale, reduce skin and eye irritation, improve filtration, and soften your swimming pool water quickly and easily - VISIBLY BRILLIANT SPARKLE: This Cal Hypo based formula sanitizes without adding cyanuric acid (CYA) to prevent overstabilization or chlorine lock - VISIBLE BLUE ACTION: This built-in feature lets you know the product is working - COMPATIBLE WITH ALL SWIMMING POOLS: This product is great for all pool types including vinyl-lined pools and saltwater systems - YOU'RE ALL CLEAR WITH HTH: For best results, use with HTH 6-Way Test Strips to test and balance your swimming pool water twice weekly; Use weekly to solve 90% of pool problems within 24 hours and restore crystal clarity ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0DC8669GD | | Best Sellers Rank | #12 in Patio, Lawn & Garden ( See Top 100 in Patio, Lawn & Garden ) #1 in Swimming Pool Chlorine | | Brand Name | HTH | | Customer Reviews | 4.8 4.8 out of 5 stars (1,245) | | Included Components | HTH 52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical | | Item Form | Tablet | | Item Type Name | Swimming Pool Chemical Prevents Bacteria, Algae, Stain & Scale, Cal Hypo Formula | | Item Weight | 4 pounds | | Manufacturer | Innovative Water Care | | Manufacturer Part Number | 52039 | | Manufacturer Warranty Description | Warranty | | Model Number | 52039 | | Number of Items | 4 | | Package Size Name | 4 Pack | | Product Benefits | Controls Algae, Kills Bacteria, Maintains Clean Sanitized Water, Prevents Stains | | Unit Count | 64 Ounce | ## Product Details - **Brand:** HTH - **Item Form:** Tablet - **Item Weight:** 4 pounds - **Number of Packs:** 4 - **Product Benefits:** Controls Algae, Kills Bacteria, Maintains Clean Sanitized Water, Prevents Stains ## Images ![52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (4 Pack) - Image 1](https://m.media-amazon.com/images/I/81qdtai1WAL.jpg) ![52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (4 Pack) - Image 2](https://m.media-amazon.com/images/I/81EarKQRSTL.jpg) ![52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (4 Pack) - Image 3](https://m.media-amazon.com/images/I/71RYVlIPduL.jpg) ![52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (4 Pack) - Image 4](https://m.media-amazon.com/images/I/81v6v8TEYIL.jpg) ![52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (4 Pack) - Image 5](https://m.media-amazon.com/images/I/717YtoLFOiL.jpg) ## Available Options This product comes in different **Size, Style** options. --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/690229473-52039-swimming-pool-care-shock-ultra-swimming-pool-chemical-cal](https://www.desertcart.hr/products/690229473-52039-swimming-pool-care-shock-ultra-swimming-pool-chemical-cal) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-08-11*