Calcium hardness

Raise your pool’s calcium hardness level quickly and efficiently. 10lb extra value size.

🚚 Free shipping on all orders 👍 30-day money back guarantee📦 Arrives in 2-4 days for orders within the domestic US

  • Boosts Hardness Fast: Elevates calcium levels to prevent corrosion, extending pool life.
  • Quick Dissolve: No fuss, no residue - just a cleaner, clearer pool in minutes.
  • Pool Surface Protector: Shields against etching and staining, keeping your pool looking new.
  • User-Friendly: Straightforward instructions for effortless pool maintenance.
  • Universal Compatibility: Works with all pool types, including chlorine and saltwater systems.
  • Trusted Quality: Made in the USA for reliable, consistent pool care.
  • 1lb of this product will raise calcium hardness by 10 ppm in a 10k gallon pool
  • If you need to increase by more than 10 ppm, multiply the dosage accordingly (e.g., to raise by 30 ppm in a 10K gallon pool, add 3lbs)
  • Broadcast (in plain English: sprinkle around widely) appropriate dosage directly into pool

Make your pool Squeaky Clean

Easy to use
Slick application methods make your DIY job a little easier
Clear video instructions
All our products have a QR code with short, easy to follow video instructions
Premium products
Simply put we source only the best, don't wonder about what's going in your pool
Save money
Customers using our products for DIY maintenance save 60% on average vs. hiring a technician
Let us help you, help your pool 🤝
You don't need a pool boy 🙅
Let us help you, help your pool 🤝
You don't need a pool boy 🙅
Your pool buddy - Your pool buddy - Your pool buddy - Your pool buddy - Your pool buddy - Your pool buddy
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Frequently Asked
Questions

Simply put, we stand by our products! If you’re not happy with the results just reach out at returns@poolday.com within 30 days of your purchase and we will help you process a return and you will get a 100% refund.

All orders at Pool Day ship free across the entire United States😎


That’s right, even you rare-breed Alaskan pool owners get our products shipped to their door for free. We are very jealous of your endless summer nights, but not so jealous of your 2-month pool season.

Right now, we only ship to the continental USA. We are hoping to expand to additional countries soon!

We are changing the pool care game.


Traditional pool chemical brands sell products with technical sounding names and instructions that are about as easy to interpret as hieroglyphics. You go to your pool store, wait in line to have your water tested, and the next thing you know you’re out a sizeable piece of your paycheck having been sold a whole assortment of products you’re not even sure you need.


Does it have to be that hard? The pool care industry doesn’t want you to know this, but the resounding answer is NO.


We are building a brand that makes it so much easier for the average pool owner to care for their own pool. With easy to understand instructions, top notch customer service and a suite of innovative products, Pool Day is making a splash. Thanks for letting us help you help your pool!