HTH 52037R Pool Care Shock Advanced, Swimming Pool Chemical - Cal Hypo Formula, Prevents Bacteria & Algae, Restores Crystal C
4.7 | 17,503 ratings
Price: 48.26
Last update: 02-02-2026
About this item
- BENEFITS: Stay all clear for cannonballs; This fast-dissolving, convenient 4-in-1 formula kills bacteria and algae, reduces chlorine odor and irritation, and quickly restores crystal clarity
- FEATURES: Multi-functional shock treatment for weekly use to solve 90% of pool water problems within 24 hours and restore crystal clarity
- VISIBLY BRILLIANT SPARKLE: This Cal Hypo based formula sanitizes without adding cyanuric acid (CYA) to prevent overstabilization or chlorine lock
- 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
Top reviews from the United States
- Kimberly SlaughKeeps My Pool Crystal Clear and Sparkling!Title: Keeps My Pool Crystal Clear and Sparkling!
This HTH pool shock works great! It clears up cloudy water fast and keeps the pool looking clean and fresh. Super easy to use — just pour it in at night, and by the next morning the water looks amazing. It dissolves quickly with no residue or strong chlorine smell. I use it weekly, and it really helps keep algae away. Excellent product and great value for regular pool maintenance! - TiffaniThe 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. - Scott W.Need these for your pool/hot tubThe HTH 52036R Pool Care Shock Advanced has become my go-to solution for keeping our hot tub water clean, clear, and safe all year long. This 6-pack is a fantastic value, and the calcium hypochlorite (cal-hypo) formula really does the job. Fast-Acting Shock Treatment: Within just a few hours of applying, the water goes from cloudy or dull to sparkling clean. It clears up algae and cloudy water impressively fast. Kills Bacteria & Prevents Algae: I’ve had issues with algae growth in the past, especially during hot, humid weeks. This shock keeps that completely under control. It also gives peace of mind that bacteria are being eliminated regularly. Each packet is pre-measured and dissolves quickly without leaving residue. No complicated mixing or measuring—just pour directly into the pool. The HTH Shock Advanced is a powerful and convenient way to maintain a clean and healthy pool. It restores clarity, controls algae and bacteria, and is very user-friendly. A pool care essential—I always keep a box on hand!
- GogiCrystal Clear Pool for My Airbnb—Easy, Effective, and Guest-Approved!HTH Pool Shock has been a game-changer for maintaining my Airbnb’s pool. It’s powerful, easy to use, and keeps the water sparkling clean—even after heavy guest use. The Cal Hypo formula works fast to eliminate bacteria and algae, and I love that it doesn’t cloud the water. Guests consistently comment on how fresh and inviting the pool looks, and this product makes it effortless to keep it that way. Highly recommend for hosts or homeowners who want reliable, professional-grade pool care without the hassle!
- MJShocked at how the price keeps risingGood product, but the price keeps going up. It dissolves quickly and work well.
- Kev01Great buy shockWorks soon much better than the cheap shock
- KristiGreat pool shockWorks great to clear up pool. Keeps water quality and ph in control.
- Mark WGood shockI like HTH brand of products. Shock works well in my pool. I can get the same brand at my local big box store and usually at the same cost. I tend to order from Amazon just to save the trip in town.