HTH 52039 Swimming Pool Care Shock Ultra, Swimming Pool Chemical, Cal Hypo Formula (4 Pack)

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

• 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