--- product_id: 540157722 title: "52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (1 Pack)" brand: "hth" price: "VT9732" currency: VUV in_stock: true reviews_count: 5 category: "Hth" url: https://www.desertcart.vu/products/540157722-52039-swimming-pool-care-shock-ultra-swimming-pool-chemical-cal store_origin: VU region: Vanuatu --- # Fast-acting 24hr clarity Prevents bacteria & algae Visible Blue Action indicator 52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (1 Pack) **Brand:** hth **Price:** VT9732 **Availability:** ✅ In Stock ## Summary > 🔵 Shock your pool to brilliance—see the blue, feel the clean! ## Quick Answers - **What is this?** 52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (1 Pack) by hth - **How much does it cost?** VT9732 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.vu](https://www.desertcart.vu/products/540157722-52039-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 - • **All-Pool Compatible:** Safe for vinyl liners, saltwater, and all pool types—versatility meets peace of mind. - • **Pro-Level Pool Care:** Use weekly with HTH 6-Way Test Strips to maintain perfect balance and crystal-clear water all season. - • **Visible Blue Action:** Unique blue tint shows you the shock is actively working—no guesswork needed. - • **Multi-Problem Solver:** Kills bacteria, prevents algae, stains, and scale while softening water and reducing irritation. - • **Sparkling Clarity in 24 Hours:** Fast-dissolving Cal Hypo formula boosts chlorine without clouding or chlorine lock. ## Overview HTH 52039 Shock Ultra is a powerful, fast-acting Cal Hypo pool treatment that elevates chlorine levels without adding cyanuric acid, preventing chlorine lock and algae growth. Its visible blue action confirms effectiveness while safely treating all pool types. This all-in-one formula kills bacteria, prevents stains and scale, softens water, and reduces skin and eye irritation, delivering sparkling clarity within 24 hours. Ideal for weekly use alongside HTH test strips, it simplifies pool maintenance for a pristine swim experience. ## 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 water—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 Review: I had this stubborn black mold looking stuff in the rubber seal around my washing machine from previous owners. I had tried everything!! Bleach, vinegar/baking soda, intense scrubbing, endless cleaning cycles, the tablets made for cleaning washing machines, etc. Nothing worked. This stuff did. Obviously be careful though, it's very potent. Review: My chlorinated discs were CYA to elevate out of control and it’s not viable for me to empty part of my pool and refill it. I let the chlorine get down under 1, added two of these bags for my 35,000 gallon pool and then had to trust the process. The first couple of days the chemical readings were concerning thinking maybe it was either working too good or not well enough, but as others have said, you need to give it 6 to 10 days to balance out which took about five days for me. We use the POOL GURU chemical messaging system, and I would not give that up. I can test as many times as I wish I can schedule it to read every day at a certain time which I do. The pool supplies are comparatively priced and the customer service is great… Using this HTH52039 swimming pool care shock ultra is a great partner to have with the guru. ## 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 | B09R81TC25 | | Brand Name | HTH | | Customer Reviews | 4.6 4.6 out of 5 stars (612) | | Global Trade Identification Number | 00073187520395 | | Included Components | HTH 52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula, 1lb | | Item Form | Powder | | Item Type Name | Swimming Pool Chemical Prevents Bacteria, Algae, Stain & Scale, Cal Hypo Formula | | Item Weight | 454 g | | Manufacturer | Innovative Water Care | | Product Benefits | Kills Bacteria | | UPC | 073187520395 | | Unit Count | 16 Ounce | ## Product Details - **Brand:** HTH - **Item form:** Powder - **Item weight:** 454 g - **Product benefits:** Kills Bacteria - **UPC:** 073187520395 ## Images ![52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (1 Pack) - Image 1](https://m.media-amazon.com/images/I/71ZLNIYD2UL.jpg) ## Available Options This product comes in different **Size, Style** options. ## Questions & Answers **Q: if this turns blue to show it is working does the water remain blue or return to clear ?** A: Ours has always turned clear. **Q: Can you use this in a hot tub?** A: There are smaller containers of shock that are reclosable and more convenient for the spa/hot tub. This package is meant for use in a large volume of water/one time use and should not be divided as the product could retain moisture or become contaminated and cause some off-gassing. Look for the shock in bottles with a lid specifically for spas, hot tubs and small pools. If you have further questions, give our team a call at 866-484-7665. **Q: Does this get rid of the algae?** A: The HTH Pool Care Shock is one of the most important parts of pool care maintenance to keep your water safe, clean and algae free. We would also recommend you use one of the HTH Pool Care Algae Guard products as part of your regular maintenance too. The Algae Guards can be part of the initial set up and weekly maintenance to make sure you keep the algae at bey. If you have other questions, or need more info, please contact us at 866-484-7665, or chat with us thru the HTHPOOLS.com website. We're Here To Help! **Q: how much do i use to make a gallon of bleach?** A: Friend, this pack of HTH Pool Care Shock is a ONE TIME USE for 10,000-12,000 gallons of water. It is not meant to be pre-mixed as that can be very dangerous due to potential off-gassing. Please ONLY follow the label directions for adding this to your swimming pool. If you need any further information or clarification about this or other HTH products, feel free to give us a call at 866-484-7665. We're Here To Help! ## Customer Reviews ### ⭐⭐⭐⭐⭐ Review *by V***S on 8 September 2025* I had this stubborn black mold looking stuff in the rubber seal around my washing machine from previous owners. I had tried everything!! Bleach, vinegar/baking soda, intense scrubbing, endless cleaning cycles, the tablets made for cleaning washing machines, etc. Nothing worked. This stuff did. Obviously be careful though, it's very potent. ### ⭐⭐⭐⭐⭐ Review *by O***5 on 3 November 2025* My chlorinated discs were CYA to elevate out of control and it’s not viable for me to empty part of my pool and refill it. I let the chlorine get down under 1, added two of these bags for my 35,000 gallon pool and then had to trust the process. The first couple of days the chemical readings were concerning thinking maybe it was either working too good or not well enough, but as others have said, you need to give it 6 to 10 days to balance out which took about five days for me. We use the POOL GURU chemical messaging system, and I would not give that up. I can test as many times as I wish I can schedule it to read every day at a certain time which I do. The pool supplies are comparatively priced and the customer service is great… Using this HTH52039 swimming pool care shock ultra is a great partner to have with the guru. ### ⭐⭐⭐⭐⭐ Review *by J***E on 12 December 2025* This product was good. It helped c;lear and clean my pool with a few shock treatments. ## Frequently Bought Together - HTH 52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (1 Pack) - Clorox Pool&Spa XTRABLUE 3” Chlorinating Tablets, Individually Wrapped, Kills Bacteria & Stops Algae (5 LB) - Clorox® Pool&Spa™ Swimming Pool Algaecide, Prevents and Treats Pool Algae, Non-Foaming, 1 Quart (Pack of 1) --- ## 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.vu/products/540157722-52039-swimming-pool-care-shock-ultra-swimming-pool-chemical-cal](https://www.desertcart.vu/products/540157722-52039-swimming-pool-care-shock-ultra-swimming-pool-chemical-cal) --- *Product available on Desertcart Vanuatu* *Store origin: VU* *Last updated: 2026-05-14*