--- product_id: 644856126 title: "HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (Pack of 6)" brand: "hth" price: "€ 252.29" currency: EUR in_stock: true reviews_count: 5 category: "Hth" url: https://www.desertcart.hr/products/644856126-hth-52040b-swimming-pool-care-shock-ultra-swimming-pool-chemical store_origin: HR region: Croatia --- # Fast-dissolving Cal Hypo formula Visible blue action indicator Compatible with all pool types HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (Pack of 6) **Brand:** hth **Price:** € 252.29 **Availability:** ✅ In Stock ## Summary > 💧 Shock your pool into sparkling perfection — see the blue, feel the clean! ## Quick Answers - **What is this?** HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (Pack of 6) by hth - **How much does it cost?** € 252.29 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/644856126-hth-52040b-swimming-pool-care-shock-ultra-swimming-pool-chemical) ## 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 - • **Rapid Clarity Boost:** Dissolves quickly to restore crystal-clear water within hours - • **Multi-Problem Solver:** Eliminates bacteria, algae, stains, and scale in one powerful treatment - • **Blue Action Assurance:** Unique blue color signals active sanitization in real-time - • **All-Pool Compatibility:** Safe and effective for vinyl, saltwater, and all pool surfaces - • **Simple, Reliable Maintenance:** Use weekly with HTH test strips to prevent 90% of pool issues effortlessly ## Overview HTH 52040B Swimming Pool Care Shock Ultra is a 6-pack of fast-acting, granular Cal Hypo pool shock that sanitizes without cyanuric acid buildup. Its visible blue action lets you track effectiveness while safely treating all pool types, including vinyl and saltwater. Designed to kill bacteria, algae, stains, and scale, it restores crystal-clear water quickly and reduces skin and eye irritation, making pool care simple and reliable for busy professionals. ## Description HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (6 Pack) Review: 12 pack was a good value - Worked well especially with all the hot days it seemed to control algae growth. Review: The only kind we purchase! - This is our first year having a pool. After trying several different shocks we settled on HTH Ultra Pool Shock.The product dissolves quickly and doesn’t leave behind any residue or cloudy water like some cheaper shock treatments I’ve tried in the past. Within a few hours of application, the water looks noticeably clearer, and it does a great job of eliminating that faint “chlorine smell” and any algae or bacteria growth. I also appreciate that the dosing instructions are straightforward, so there’s no guessing game when treating different pool sizes. One packet is usually enough to restore balance after a heavy swim day, rainstorm, or when the water just starts to look a little dull. It gives me peace of mind knowing that my family is swimming in clean, well-sanitized water. Overall, HTH Ultra Pool Shock is reliable, effective, and worth the price for the results you get. If you want a hassle-free way to maintain crystal-clear water, I highly recommend it. ## Features - 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 | B09R81TQBS | | Brand | HTH | | Brand Name | HTH | | Customer Reviews | 4.8 out of 5 stars 576 Reviews | | Included Components | HTH 52040 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (Pack of 6) | | Item Form | Granular | | Item Type Name | Swimming Pool Chemical Prevents Bacteria, Algae, Stain & Scale, Cal Hypo Formula | | Item Weight | 6.3 Pounds | | Item form | Granular | | Item weight | 6.3 Pounds | | Manufacturer | Innovative Water Care | | Manufacturer Part Number | 52040B | | Model Number | 52040B | | Number of Items | 1 | | Number of Packs | 6 | | Package Size Name | 6 Pack | | Product Benefits | Kills Bacteria | | Product benefits | Kills Bacteria | | UPC | 073187520401 | | Unit Count | 6 Count | ## Product Details - **Brand:** HTH - **Item form:** Granular - **Item weight:** 2.86 kg - **Product benefits:** Kills Bacteria - **UPC:** 073187520401 ## Images ![HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (Pack of 6) - Image 1](https://m.media-amazon.com/images/I/81aKILdYRbL.jpg) ![HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (Pack of 6) - Image 2](https://m.media-amazon.com/images/I/81lT7q44+SL.jpg) ![HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (Pack of 6) - Image 3](https://m.media-amazon.com/images/I/71RYVlIPduL.jpg) ![HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (Pack of 6) - Image 4](https://m.media-amazon.com/images/I/81v6v8TEYIL.jpg) ![HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (Pack of 6) - Image 5](https://m.media-amazon.com/images/I/716YqOgZNjL.jpg) ## Questions & Answers **Q: Can this replace weekly chlorine?** A: This is a sanitizer that is used as weekly shock or your regular sanitizer maintenance. The amount you use for weekly shock and the amount for maintenance is different based upon the pool water volume. Ideally, this is used for Shock but we can help with regular maintenance dose if you choose to not use a tablet in your skimmer. Please consider calling our Consumer Engagement Team for more precise recommendations and dosing details. We're available M-F, 9 AM - 7 PM at 866-484-7665. **Q: What is the percentage of available chlorine?** A: This product has 56.44% available chlorine. **Q: How long do you have to wait after adding shock before you can swim?** A: The general rule is to wait at least an hour per pound of granular product, to allow it to dissolve and dilute properly. Before you enter the pool, make sure to test and that the chlorine level is between 1-4 ppm (and NOT ABOVE 5 ppm) for the safest swimming. **Q: 1 bag treats how many gallons water** A: We are the manufacturer of HTH® Pool Care Shock Ultra and one of our 1 lb. bags treats 13,500 gallons of swimming pool water. If you have any more questions just give us a call at 866-484-7665. ## Customer Reviews ### ⭐⭐⭐⭐⭐ 12 pack was a good value *by E***E on 21 July 2026* Worked well especially with all the hot days it seemed to control algae growth. ### ⭐⭐⭐⭐⭐ The only kind we purchase! *by T***I on 17 September 2025* This is our first year having a pool. After trying several different shocks we settled on HTH Ultra Pool Shock.The product dissolves quickly and doesn’t leave behind any residue or cloudy water like some cheaper shock treatments I’ve tried in the past. Within a few hours of application, the water looks noticeably clearer, and it does a great job of eliminating that faint “chlorine smell” and any algae or bacteria growth. I also appreciate that the dosing instructions are straightforward, so there’s no guessing game when treating different pool sizes. One packet is usually enough to restore balance after a heavy swim day, rainstorm, or when the water just starts to look a little dull. It gives me peace of mind knowing that my family is swimming in clean, well-sanitized water. Overall, HTH Ultra Pool Shock is reliable, effective, and worth the price for the results you get. If you want a hassle-free way to maintain crystal-clear water, I highly recommend it. ### ⭐⭐⭐⭐⭐ Shocked *by M***K on 24 May 2026* Works well. ## Frequently Bought Together - HTH 52040B Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb (6 Pack) - HTH 67067 Swimming Pool Care Clarifier Advanced - Crystal Clear Water in 24 Hours - HTH 52038 Swimming Pool Care Green to Blue, Advanced Shock System, 2-Step Swimming Pool Care Solution, 1 Kit --- ## 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/644856126-hth-52040b-swimming-pool-care-shock-ultra-swimming-pool-chemical](https://www.desertcart.hr/products/644856126-hth-52040b-swimming-pool-care-shock-ultra-swimming-pool-chemical) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-07-30*