Search  for anything...

Calcium Hypochlorite Granular for Swimming Pools, 1lb (Pack of 24)

Based on 6,415 reviews
Condition: New
Product info up-to-date
$84.99
Save $14.64 was $99.63

Buy Now, Pay Later


As low as $14.17 / mo
  • – 6-month term
  • – No impact on credit to apply
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout.

Payment plans are offered through our trusted finance partners Klarna, Affirm, Afterpay, Zip, Apple Pay, and Google Pay. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.


Availability: In Stock.
Fulfilled by MyGardenPool

Arrives Thursday, Nov 19
Order within 14 hours and 18 minutes

Available payment plans shown during checkout

Protect Your Purchase

Easy claims online, fast replacements, no fees

Checking for protection plans...

At a glance

Condition
New
Size
24-Pack
Model
1-1901--24
Weight
24 lb
Item Form
Granular
Item Type Name
Pool Shock

Features 5

  • High Chlorine Content: Contains 68% available calcium hypochlorite, delivering powerful sanitizing and disinfecting performance.
  • Fast-Dissolving Granules: Ensures quick and consistent solution preparation, ideal for potable water and industrial applications.
  • No Cyanuric Acid: Cyanuric acid-free formula prevents buildup and maintains water clarity, making it suitable for drinking water systems.
  • Meets Regulatory Standards: Complies with NSF Standard 60 and AWWA B300-05, confirming its safety and effectiveness for water treatment.

Description

DryTec 23205 Calcium Hypochlorite Granules – NSF Certified Water Treatment Solution (68% Available Chlorine) Keep your water clean, safe, and crystal clear with DryTec 23205 – a high-performance calcium hypochlorite sanitizer trusted by professionals for potable water systems, industrial sanitation, and emergency purification. With 68% available chlorine, these fast-dissolving granules deliver powerful disinfection without the buildup of stabilizers like cyanuric acid. Powerful Disinfection – Effectively eliminates bacteria, viruses, and algae with high-strength calcium hypochlorite. NSF/ANSI Standard 60 Certified – Safe for use in drinking water systems and municipal treatment facilities. Cyanuric Acid-Free Formula – Prevents cloudy water and chemical lock, ideal for long-term use. Fast-Dissolving Granules – Easy to apply and mix, ensuring consistent chlorine levels. Versatile Applications – Suitable for emergency water purification, industrial sanitation, and routine water maintenance. Package Includes: 24 pack of 1lb bags of DryTec 23205 Calcium Hypochlorite Granules Usage: Follow dosage instructions based on water volume and treatment needs. Store in a cool, dry place.

Specs 14

Brand DryTec
Item Weight 24 pounds
Item Form Granular
Product Benefits Destroys Organic Contaminants,Kills Bacteria,Controls Algae
Brand Name DryTec
UPC 034261003944
Number of Packs 24
Package Size Name 24-Pack

Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Thursday, Nov 19

This item is non-returnable:

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • Zip Pay in 4
  • Financing through Apple Pay
  • Financing through Google Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Top Amazon Reviews


Dependable product
Size: 24-Pack
Great convenient value! The DryTec calcium hypochlorite dissolves well and helps get the pool water clean, clear, and fresh. The individual 1-pound packages make it easy to measure and use without any mess or guesswork. Having a 24-pack on hand is especially convenient for regular pool maintenance. Overall, a dependable product that makes keeping the pool in great condition much easier. ... show more
Reviewed in the United States on September 19, 2026 by MM- Stafford, Virginia

Love this pool shock 68%Calcium Hypochlorite
Size: 24-Pack
I did a lot of research before I purchased this DryTec brand of hypochlorite chlorine pool shock. I usually use “In The Swim “brand of chemicals in my pool but when I was on Amazon I came across the DryTec . It got great reviews. I used my perplexity AI search engine and googled it as well. Nice high quality product works well . It’s 68% Calcium Hypochlorite. So it’s nice and strong. It keeps my water crystal clear. It’s very easy to use. I have an in ground gunite pool so I just open the bag and disperse it over the water in my deep end.My pool had 33,000 gallons of water so I use 3 one pound bags per application. I usually use it preventively once every 4 weeks. I don’t understand what a company that makes compressed air equipment has to do with pool chemicals but this company makes a great pool shock. I get the 24 pack size it was $114 last time I ordered it which is a great price. It’s is as good or better than the In The Swim shock I use to use. ... show more
Reviewed in the United States on June 26, 2025 by William

Shock & Awe: The Terminator of Pool Shocks
Size: 24-Pack
I travel frequently, sometimes for extended periods of time, which makes pool maintenance without hiring a service a real pain. This is particularly troublesome with an in-ground pool in Florida in Summer that has no shade. I waited to post a review until after I'd ordered 2 separate batches to test for quality control, and quite simply: this is the BEST shock I've ever used. I've come back from trips to solid green slime pits with heavy stripes of the dreaded black spot algae, and 2-3bags of this stuff + a couple of chlorine tablets with the filter running will turn my pool back to blue overnight. Like other reviewers, I have noticed that my water is a little cloudy the next 24-32hrs--- but in my case, I chalk that up to so much dead organic material & algae that needs to be filtered out. This stuff kills ALL the nasty stuff--- but until it's vacuumed or filtered out, it's still in the water. It works when nothing else does, and does a better & faster job. It's also priced very competitively. If you have a problem pool, or a problem with regular maintenance, this stuff is AMAZING. It terminates even the most durable, hardened, and persistent algae with extreme prejudice, you just have to give your vacuum or filter a chance to clear the battlefield of all the millions of algae corpses once it's finished annihilating them, and then declare unconditional victory. If you're just looking for regular pool maintenance, this may be a little strong for your needs. I will say that when I'm around to take care of it, one bag of this every 2-3 weeks, plus a couple of chlorine tablets does the trick (without cloudiness). Where it really shines though is in rehabilitating seemingly terminally green monsters back into beautiful blue pools. ... show more
Reviewed in the United States on September 20, 2017 by Eryn Lockhart

For the price this is an excellent product.
Size: 24-Pack
I really like this pool shock, it is every bit as good as the Leslie's product and half the price. The granules dissolve quickly and the chlorine levels work well in targeting bacterial growth. The only complaint I have is that the bags will melt together, if stored in very high heat areas. I have a large plastic storage bin, that is located in direct sunlight, that I store my pool chemicals in, and the shock bags will melt in the summer months. Not really a huge issue, as I just store the bags in the garage now and they are fine, but I wanted to let others know about this minor issue. ... show more
Reviewed in the United States on February 3, 2024 by Scott Taylor

It just flat out works!
Size: 24-Pack
I love this shock! I have used plenty of other brands and nothing I have used seems to work quite as well as Drytec does. In only about 7 to 10 minutes, see the difference between the first two pictures. The next day my pool is totally clear and blue again, amazing! My pool is roughly 33,000 gallons and I used (3) of the 1lb bags. ... show more
Reviewed in the United States on June 6, 2026 by BigNate

Powerful and Reliable Pool Shock for Crystal Clear Water
Size: 24-Pack
Powerful and Reliable Pool Shock for Crystal Clear Water This 24-pack of Drytec 1-pound calcium hypochlorite bags has been a real workhorse in keeping my pool sparkling. Each bag is individually sealed, making it simple to grab one, cut it open, and pour without mess. I like that the packaging is compact and easy to store in the garage, and the dosing is straightforward—one bag at a time keeps me from over- or under-chlorinating. Performance-wise, this shock works quickly. I usually add it in the evening, and by the next morning the water is clear, bright, and free of that slightly cloudy look that creeps up during heavy use. It’s strong enough to handle algae blooms after a stretch of hot weather but doesn’t leave any noticeable residue once fully dissolved. A couple of things to keep in mind: this is calcium hypochlorite, so it does raise calcium levels over time. That isn’t a problem for me since my pool water tends to run soft, but if you already have high calcium hardness, you’ll want to monitor it to avoid scaling. Also, because it’s strong, I always pre-dissolve in a bucket and add it slowly to avoid bleaching spots on the liner. Bottom line: A reliable, cost-effective pool shock that’s easy to use and keeps water crystal clear—just keep an eye on calcium levels if your pool runs hard water. ... show more
Reviewed in the United States on September 9, 2025 by Everyday Reviews

EXCELLENT VALUE IF USED WISELY
Size: 24-Pack
TO AOID ANY BURNS TO LINER PUT 2-3 LBS DRY-TEC IN 5 GALLON OR LARGER BUCKET. FILL WITH WATER FROM POOL WITH ANOTHER BUCKET OR HOSE ETC. STIR VIGOROUSLY WITH A PIECE OF WOOD F A EW SECONDS . LET SIT A MINUTE OR TWO. POUR OFF ABOUT 3/4 OF WATER BACK INTO POOL RETURN AREA WHILE FILTER RUNNING. RE-FILL AND REPEAT. UNTIL NO CL RESIDUE IS LEFT IN BOTTOM OF BUCKET ... show more
Reviewed in the United States on August 1, 2026 by brianD

Excellent product!!
Size: 24-Pack
I always read reviews before making a purchase on Amazon. That’s one of the reasons I shop here. This pool shock is an excellent product. I know I’m being price gauged with both the shock and the chlorine tabs. There is no excuse for that. Thankfully, we are all free to shop for better prices. Although still pricey, it beats most competitors. This product easily dissolved in my pool, just like it should do. I had an algae problem because my brand new motor was circulating too low. I had no water movement. There’s always a reason for algae. After scrubbing the sides many times and working like a Trojan, I added 2 packs of this stuff one day, and 3 packs the next. I got my motor reset, thank you EPA for trying to help me. Yuk, I don’t care how many hours or at what speed I need to have clear water, but stop helping me, PLEASE!!!! This product is great. Don’t hesitate!!!! ... show more
Reviewed in the United States on April 30, 2024 by sharont