One-time purchase:
$44.86
FREE delivery Wednesday, May 22
Ships from: Amazon.com
Sold by: Amazon.com
FREE Returns
FREE delivery Wednesday, May 22. Order within 23 hrs 8 mins
Only 12 left in stock (more on the way).
$$44.86 () Includes selected options. Includes initial monthly payment and selected options. Details
Price
Subtotal
$$44.86
Subtotal
Initial payment breakdown
Shipping cost, delivery date, and order total (including tax) shown at checkout.
Ships from
Amazon.com
Ships from
Amazon.com
Sold by
Amazon.com
Sold by
Amazon.com
Returns
30-day easy returns
30-day easy returns
This item can be returned in its original condition for a full refund or replacement within 30 days of receipt.
Read full return policy
Returns
30-day easy returns
This item can be returned in its original condition for a full refund or replacement within 30 days of receipt.
Read full return policy
Payment
Secure transaction
Your transaction is secure
We work hard to protect your security and privacy. Our payment security system encrypts your information during transmission. We don’t share your credit card details with third-party sellers, and we don’t sell your information to others. Learn more
Payment
Secure transaction
We work hard to protect your security and privacy. Our payment security system encrypts your information during transmission. We don’t share your credit card details with third-party sellers, and we don’t sell your information to others. Learn more
Save up to 5% on auto-deliveries.

Unlock 5% savings

Save 5% when you receive 5 or more products in one auto-delivery to one address.

Choose how often it's delivered

From once every 2 weeks to once every 6 months

Skip or cancel any time

We'll send you a reminder before each delivery.
Learn more
FREE delivery Wednesday, May 22. Order within 23 hrs 8 mins
Only 12 left in stock (more on the way).
Deliver every:
×

Added to cart

$$44.86 () Includes selected options. Includes initial monthly payment and selected options. Details
Price
Subtotal
$$44.86
Subtotal
Initial payment breakdown
Shipping cost, delivery date, and order total (including tax) shown at checkout.
Ships from and sold by Amazon.com
Add an Accessory:
Robelle 1405M Chlorine Tabs Pool Sanitizer, 5-Pounds
$53.83
Added to Cart
Robelle 2205B pH Up for Pools, 5-Pounds
$15.82
Added to Cart
Robelle 2255B Alkalinity Increaser for Swimming Pools, 5-Pounds
$14.54
Added to Cart
Robelle 2306B pH Down for Pools, 6-Pounds
$15.22
Added to Cart

Robelle 2825 Calcium Hardness Increaser for Pools, 25-Pounds

4.6 4.6 out of 5 stars 1,305 ratings
$44.86
FREE Returns
25-Pounds (Bucket)
water treatment
{"desktop_buybox_group_1":[{"displayPrice":"$44.86","priceAmount":44.86,"currencySymbol":"$","integerValue":"44","decimalSeparator":".","fractionalValue":"86","symbolPosition":"left","hasSpace":false,"showFractionalPartIfEmpty":true,"offerListingId":"3lsI6AbPjp%2Frg44GPn%2FJ9%2BUXJavPz4U6fc2fSVRYYS3bgnMXxeqGJi5E30bjaB1NIjm%2BrsrYSBuB1lwqfeC%2F1Nk82xLG6jaPUeCofZfUavRzExmpFYMkpgsXiswqgSXW2JuyYB%2BTnIOKBTf6HfF11Q%3D%3D","locale":"en-US","buyingOptionType":"NEW","aapiBuyingOptionIndex":0}, {"displayPrice":"$44.86","priceAmount":44.86,"currencySymbol":"$","integerValue":"44","decimalSeparator":".","fractionalValue":"86","symbolPosition":"left","hasSpace":false,"showFractionalPartIfEmpty":true,"offerListingId":null,"locale":"en-US","buyingOptionType":"SNS","aapiBuyingOptionIndex":1}]}

Purchase options and add-ons

Brand Robelle
Item Weight 25 Pounds
Item Form Granular
Product Benefits Calcium Increaser

About this item

  • Calcium chloride for pools
  • Rapidly increases total hardness
  • Helps prevent corrosion or etching of pools
  • Ideal calcium hardness range 200 - 400 ppm
  • 8 ounces raises calcium hardness level 10 ppm per 5,000 gallons of water
  • Prevents the staining or etching of your pool's surface
  • Low calcium hardness level can cause water issues

Customer ratings by feature

Easy to use
4.4 4.4
Value for money
4.3 4.3
Style
4.3 4.3
See all reviews

Frequently bought together

Robelle 2825 Calcium Hardness Increaser for Pools, 25-Pounds
$44.86
Get it as soon as Wednesday, May 22
Only 12 left in stock (more on the way).
Ships from and sold by Amazon.com.
+
Clorox® Pool&Spa™ Swimming Pool Chlorine Stabilizer, Helps Chlorine Last Longer, Saltwater Pool Compatible, 4LB (Pack of 1)
$15.99 ($0.25/Ounce)
Get it as soon as Wednesday, May 22
In Stock
Ships from and sold by Amazon.com.
+
In The Swim Alkalinity Increaser for Swimming Pools - Raises Alkalinity and Balances pH Levels in Your Swimming Pool Water -
$44.99 ($0.11/Ounce)
Get it as soon as Monday, May 20
In Stock
Ships from and sold by In The Swim Pool Supplies.
Total price:
To see our price, add these items to your cart.
Details
Added to Cart
Some of these items ship sooner than the others.
Show details Hide details
Choose items to buy together.

From the brand

Previous page
  2. Balanced Pool Water Ensures Sanitizer Efficiency, Swimmer Comfort and clear and helthy pool water
  3. Robelle 2607B Stabilizer for Swimming Pools, 7 lb
    Robelle 2256B Total Alkalinity Increaser for Swimming Pools, 10 lb
    Robelle 2205B pH Increaser for Swimming Pools, 5 lb
    Robelle 2825 25 Pounds Pool Calcium Increaser, 25-Pounds (Bucket)

    Step 1: Balance

    Visit the Store

  4. Sanitize with Robelle Chlorine: Kills Bacteria, Inhibits algae growth, Purifies and Disinfects
  5. Robelle 1405M Chlorine Tabs Pool Sanitizer, 5-Pounds
    Robelle 1410M Chlorine Tabs Pool Sanitizer, 10-Pounds
    Robelle 1420M Chlorine Tabs Pool Sanitizer, 20-Pounds
    Robelle 1440M-K 5-in-1 3-Inch Multi-Purpose Swimming Pool Chlorine Tabs, 35-Pounds

    Step 2: Sanitize

    Visit the Store

  6. Rejuvenate your pool water once a week with Robelle Shock
  7. Robelle 1701-12 Oxidizing Shock and Swim Monopersulfate Non-Chlorine Pool Shock, 1-Pound, 12-Pack
    Robelle 1701-24 Non-Chlorine Swimming Pool Shock, 24-Pack
    Dry Tec 1-1901-12 Treatment Pool Shock, 12-Pack
    DryTec 1-1901-24 Calcium Hypochlorite Chlorine Shock Treatment for Swimming Pools, 1-Pound, 24-Pack

    Step 3: Shock

    Visit the Store

  8. Prevent growth and treat existing algae with Robelle Algaecide.
  9. Pool Mate 1-2150-02 50 Pool Algaecide, 2-Pack
    Pool Mate 1-2150-04 50 Pool Algaecide, 4-Pack
    Pool Mate 1-2190-02BX Black Pool Algaecide, 2-Pack
    Pool Mate 1-2190-04 Black Pool Algaecide, 4-Pack

    Step 4: Algae Control

    Visit the Store

  10. Further Maintenance: Clarifiers and Stain Removers
  11. Robelle 2420-02 Water Brightener and Clarifier for Swimming Pools, 1-Quart, 2-Pack
    Robelle 2420-04 Water Brightener and Clarifier for Swimming Pools, 1-Quart, 4-Pack
    Robelle 2550-02 Mineral Out Stain Remover for Swimming Pools, 1-Quart, 2-Pack
    Robelle 2550-04 Mineral Out Stain Remover for Swimming Pools, 1-Quart, 4-Pack

    Further Maintenance

    Visit the Store

Next page

Product information

Warranty & Support

Manufacturer’s warranty can be requested from customer service. Click here to make a request to customer service.

Feedback

Robelle 2825 Calcium Hardness Increaser for Pools, 25-Pounds

Robelle 2825 Calcium Hardness Increaser for Pools, 25-Pounds

Found a lower price? Let us know. Although we can't match every price reported, we'll use your feedback to ensure that our prices remain competitive.

Where did you see a lower price?

Fields with an asterisk * are required
/
/
/
/
Please sign in to provide feedback.

Looking for specific info?

Product guides and documents

User Guide (PDF)

Product Description

This is a dry granular product that increases the total hardness in pool water to the recommended range.Test for calcium hardness with a reliable test kit. The desired range for calcium hardness is as follows: Vinyl Pools: 200-300 ppm, Tile and Exposed Aggregate Pools: 200-400 ppm, Marcite, Fiberglass or Painted Pools: 250-400 ppm. If the calcium hardness tests less than the desired range, add this product according to the included chart. Place this product into a plastic bucket already filled with swimming pool water. Do this in a ration of up to 2 pounds of product per approximate 5-gallon bucket of water. Slowly pour this solution around the perimeter of the swimming pool while the circulating system is operating. In a 10,000 gallon pool, do not add more than 10 pounds of this product per 2 hour period.

Compare with similar items

This Item
Robelle 2825 Calcium Hardness Increaser for Pools, 25-Pounds
Robelle 2825 Calcium Hardness Increaser for Pools, 25-Pounds
Recommendations
In The Swim Calcium Hardness Increaser for Swimming Pools - Fast-Acting, Scale Prevention - 94% Calcium Chloride - 45 Pounds
In The Swim Calcium Hardness Increaser for Swimming Pools - Fast-Acting, Scale Prevention - 94% Calcium Chloride - 45 Pounds
dummy
Quality Producer Direct Calcium Hardness Increaser (1 Gallon) Calcium Chloride Powder for Pools & Hot Tubs
Quality Producer Direct Calcium Hardness Increaser (1 Gallon) Calcium Chloride Powder for Pools & Hot Tubs
dummy
Calcium Chloride Pool Hardness Increaser | Spa Calcium Hardness Increaser | Works for Pools Spa & Hot Tub | Hot Tub Chemicals | Pool Chemicals | SPA Chemicals
ECO LIVING SOLUTIONS Calcium Chloride Pool Hardness Increaser | Spa Calcium Hardness Increaser | Works for Pools Spa & Hot Tub | Hot Tub Chemicals | Pool Chemicals | SPA Chemicals
dummy
HTH 67059 Swimming Pool Care Calcium Hardness Up, Swimming Pool Chemical Protects Swimming Pool Surfaces and Liners, 4 Lbs
HTH 67059 Swimming Pool Care Calcium Hardness Up, Swimming Pool Chemical Protects Swimming Pool Surfaces and Liners, 4 Lbs
dummy
Clorox® Pool&Spa™ Swimming Pool pH Down, Lowers pH, Protects Against Eye and Skin Irritation, 5LB (Pack of 1)
Clorox Pool & Spa Clorox® Pool&Spa™ Swimming Pool pH Down, Lowers pH, Protects Against Eye and Skin Irritation, 5LB (Pack of 1)
Details
Added to Cart
Details
Added to Cart
Details
Added to Cart
Details
Added to Cart
Details
Added to Cart
Details
Added to Cart
Price$44.86-6% $84.99
List: $90.54		$27.49$25.95$14.99-27% $7.99
List: $10.99
Delivery
Get it as soon as Wednesday, May 22
Get it as soon as Monday, May 20
Get it as soon as Wednesday, May 22
Get it as soon as Wednesday, May 29
Get it as soon as Wednesday, May 22
Get it as soon as Wednesday, May 22
Customer Ratings
4.64.6 out of 5 stars1,305
4.74.7 out of 5 stars972
4.54.5 out of 5 stars196
4.64.6 out of 5 stars69
4.74.7 out of 5 stars76
4.74.7 out of 5 stars5,613
Easy to use
4.4
4.8
5.0
4.4
—
4.5
Value for money
4.3
4.7
5.0
4.0
—
4.2
Style
4.3
5.0
—
4.0
—
—
Sold By
Amazon.com
In The Swim Pool Supplies
Axio Supply
Eco Garden Solutions
Amazon.com
Amazon.com
form
Granular
Granular
Powder
Liquid
—
Granular
weight
25 pounds
48 pounds
—
—
4 pounds
5 pounds

Customer reviews

4.6 out of 5 stars
4.6 out of 5
1,305 global ratings

Customers say

Customers like the value, performance, quality and dissolves of the pool spa water treatment. They mention that it works great, it's affordable and that it dissolves quickly. They appreciate the calcium increaser, and ease of use. However, some customers have reported issues with the lid. They also dislike the water quality.

AI-generated from the text of customer reviews

48 customers mention48 positive0 negative

Customers find the value of the pool spa water treatment to be reasonable. They mention that it's an economical way to increase calcium.

"I like saving money, and this is much cheaper than what is charged at our local pool store...." Read more

"...Supply store and is better price" Read more

"...This was reasonably priced with a deal and has served its purpose. Pool is happy and so am I." Read more

"Perfect for our hot tub water adjustment at a great price! Thanks." Read more

35 customers mention35 positive0 negative

Customers are satisfied with the performance of the pool spa water treatment. They mention that it works well to increase hardness, tame R/O water, and improves water quality immediately. Some say the packaging could be improved.

"...Worked just fine when we needed to add calcium to our pool water" Read more

"Product worked exactly as stated , saves me trip from going to poolSupply store and is better price" Read more

"Applied to garden tomatoes and tomatillos - big improvement immediately. Recommended if you need Calcium." Read more

"Product is good. Gave 1 less star because the bag was busted inside the box, leaving a mess on the bottom." Read more

17 customers mention17 positive0 negative

Customers are satisfied with the quality of the pool spa water treatment. They mention it's a great buy, high quality, and better than name brands. Some say it'll be a perfect addition to their salt water pool and help raise the CA level.

"Easy to use, better than name brand...." Read more

"Good transaction shipped quick and good product" Read more

"Great Product!" Read more

"Nice and it keeps my number looking good" Read more

14 customers mention11 positive3 negative

Customers like the dissolves of the pool spa water treatment. They mention that it dissolves quickly and does not clump at all.

"...This was much cheaper and delivered to my door. Dissolves fairly easily putting bout 4 pounds at a time in 5 gallons of water with some stirring...." Read more

"...It dissolves very quickly and it did not clump at all...." Read more

"...It dissolved so quickly in my 14' current pool -- I added a cup of calcium at the front, and by the time the current reached the back of the pool, I..." Read more

"Good product, dissolves fast, easy to use!" Read more

8 customers mention8 positive0 negative

Customers are satisfied with the calcium increaser. They mention that it increases the hardness of the pool water at the rate as suggested on the package. They also say that it's great for swimming pool hardness increase and helps reduce calcium from being pulled from the pool. However, some customers have reported that the lid came off.

"Increases calcium hardness in your hot tub.... prevents corrosion." Read more

"The actual calcium chloride seems fine, but as has happened to others, the lid came off during transit (via Amazon Prime delivery)...." Read more

"I have no complain about this product. It increased the calcium hardness in the pool at the rate as suggested on the package. I would buy it again." Read more

"Improves the hardness of your pool water which can help reduce calcium from being pulled from the plaster and Gunite...." Read more

8 customers mention8 positive0 negative

Customers find the pool spa water treatment easy to use and convenient. They also appreciate the clear instructions and convenience.

"Easy to use, better than name brand...." Read more

"Good product, dissolves fast, easy to use!" Read more

"needed this for the pool did a good job easy to use love it ty" Read more

"Easy to use, great packaging and fairly-priced. Thank You!" Read more

9 customers mention0 positive9 negative

Customers are dissatisfied with the lid of the pool spa water treatment. They mention that it buckles, pops off during transit, and is flimsy. Some say that the bag was ripped upon arrival and the product was spilled out.

"Product is good. Gave 1 less star because the bag was busted inside the box, leaving a mess on the bottom." Read more

"...chloride seems fine, but as has happened to others, the lid came off during transit (via Amazon Prime delivery)...." Read more

"...Tub has a flimsy lid and was inserted into a box on its side. The picture results are self explanatory...." Read more

"Good value on Calcium, but the thin plastic interior bag was ripped upon arrival and there was loose, damp/wet calcium everywhere. What a mess...." Read more

7 customers mention0 positive7 negative

Customers are dissatisfied with the water quality of the pool spa water treatment. They mention that the water is still cloudy, condensation builds on the granules, and the inner bag was wet.

"...interior bag was ripped upon arrival and there was loose, damp/wet calcium everywhere. What a mess...." Read more

"...Followed instructions to a tee but pool got cloudy, never happened with other brands. Best to avoid this brand if you can." Read more

"...Three days later, my water is still cloudy and my chorine demand is through the roof. It does...." Read more

"...However box was a bit beat up and the inner bag wet. If you know about Calcium Chloride you know what happens when it gets wet...." Read more

Flimsy tub lid.
4 Stars
Flimsy tub lid.
Product is okay, but someone needs to go back to Packing 101 class. Tub has a flimsy lid and was inserted into a box on its side. The picture results are self explanatory.Won’t be purchasing this again unless the product is packaged in a better container to take the abuse.
Hide
Thank you for your feedback
Sorry, there was an error
Sorry we couldn't load the review

Top reviews from the United States

Dianne
5.0 out of 5 stars Less expensive than buying from pool store, works great
Reviewed in the United States on January 30, 2024
Size: 10-PoundsStyle: water treatmentVerified Purchase
I like saving money, and this is much cheaper than what is charged at our local pool store. Worked just fine when we needed to add calcium to our pool water
Helpful
 Report
Aimee savage
5.0 out of 5 stars Good product
Reviewed in the United States on September 14, 2023
Size: 4-Pounds (Bucket)Style: water treatmentVerified Purchase
Product worked exactly as stated , saves me trip from going to pool
Supply store and is better price
Helpful
 Report
LRA
5.0 out of 5 stars Worked great.
Reviewed in the United States on May 11, 2024
Size: 16-PoundsStyle: water treatmentVerified Purchase
Half the price of our pool store and did the job.
Helpful
 Report
Randi
4.0 out of 5 stars Worked good
Reviewed in the United States on March 12, 2024
Size: 25-Pounds (Bag)Style: water treatmentVerified Purchase
Good stuff poor packaging
Helpful
 Report
Amazon Customer
5.0 out of 5 stars Good Stuff
Reviewed in the United States on May 13, 2024
Size: 8-PoundsStyle: water treatmentVerified Purchase
Great Product for a fraction of the Pool store Priced
Helpful
 Report
Wendell Broussard
5.0 out of 5 stars Good calcium increaser
Reviewed in the United States on August 19, 2023
Size: 25-Pounds (Bag)Style: water treatmentVerified Purchase
I needed some calcium chloride for a pool, but had trouble finding any locally and even more trouble finding it online in bulk where it didn't cost an arm and a leg. This was reasonably priced with a deal and has served its purpose. Pool is happy and so am I.
Helpful
 Report
Florida Customer
5.0 out of 5 stars Works great
Reviewed in the United States on March 18, 2024
Size: 8-PoundsStyle: water treatmentVerified Purchase
Cheaper than purchasing the same item at the store and it was delivered to my house.
Helpful
 Report
S. Smith
5.0 out of 5 stars Exactly as expected!
Reviewed in the United States on November 24, 2023
Size: 4-PoundsStyle: water treatmentVerified Purchase
Perfect for our hot tub water adjustment at a great price! Thanks.
Helpful
 Report