Calcium Hardness Increaser
PassCalcium Hardness Increaser scores 66 out of 100, a Pass. Shoppers spend an estimated $1.7M a year here, search demand grew +313.5% this quarter, and an estimated 0.4% of orders come back.
- Flapen Score
- 66 / 100Top 13% of 8,839 Patio, Lawn & Garden niches · +10 vs the category median of 5666
- Market size
- $1.7M/yr237K searches / yr
- 90-day growth
- +313.5%search demand this quarter
- Competition
- 77%top-5 click share · 7 brands · 39 sellers
Flapen Score
Calcium Hardness Increaser against its category
The dotted line is the Patio, Lawn & Garden average. Past it, Calcium Hardness Increaser is stronger. Inside it, weaker.
Market
The Calcium Hardness Increaser market on Amazon at a glance
Shoppers on Amazon United States searched for Calcium Hardness Increaser 237K times last year and spent an estimated $1.7M. The top 5 brands take 94% of clicks. Demand peaks in May–Jun–Jul. Flapen scores it 66 out of 100, a Pass.
01 · Demand
An estimated 22.7% of those searches ended in a purchase.
Shoppers searched for this 237K times in the last 12 months. That counts every search on Amazon United States for this niche's terms. An estimated 22.7% of those searches ended in a purchase. Searches in the last 90 days moved +313.5% against the 90 days before. Searches, conversion and average price together put the market at an estimated $1.7M a year.
- Searches, last 12 months
- 237K
- Growth, 90 days vs prior 90
- +313.5%
- Conversion, latest week
- 22.7%
- Market size, estimated
- $1.7Ma year
- Peak month
- June13.3× the quietest month
- Top search term
- calcium hardness increaser81K searches a year
02 · Price
A sale here is worth $31.15.
Listings sell for $31.15 on average, from $9.38 to $80.18. Amazon reports units sold in ranges. This niche sold 50K to 60K a year. The average listing sells 4,000 to 5,000 of them. At $31.15 that is $125K to $156K a year per listing.
- Average price
- $31.15inside the $15 to $100 sweet spot
- Price range
- $9.38–$80.18
- Amazon United States median price
- $24.38across 115,062 niches
- Units sold a year
- 50K–60K
- Units per listing a year
- 4,000–5,000
- Revenue per listing a year
- $125K–$156K
- Returns
- 0.4%of orders · Amazon United States median 2.1%
03 · Entry bar
The bar here is ads and reviews.
100% of listings pay for placement with sponsored ads. 85% ship with Prime. On an average day, 0.0% of listings are out of stock. The average listing ranks #48 within Cleaning Tools & Chemicals. It carries 1,511 reviews at 4.70 stars, so a new listing needs social proof before a better product.
- Sponsored listings
- 100%
- Prime listings
- 85%
- Out of stock, average day
- 0.0%
- Average rank
- #48in Cleaning Tools & Chemicals
- Average rating
- 4.70 starsAmazon United States average 4.42 stars
- Average reviews
- 1,511per listing
- Listings tracked
- 13
04 · Newcomers
Brands here are established.
The brands on the shelf have sold for 79 months on average, so the names here are established.
- Launched, last 12 months
- 0
- Successful launches
- 0Amazon's first-year sales bar
- Average brand age
- 79 months
Products
Top Calcium Hardness Increaser products & what they sell for
The products selling here, as shoppers see them on Amazon. Shelf share and sales are our estimates.
Prices and ratings read from Amazon on Jul 24, 2026. The live listing can differ.
Top sellers
by estimated 90-day click share
Clorox Pool&Spa Swimming Pool Calcium Hardness Increaser Prevents Corrosion Etching and Staining 4LB (Pack of 1)
- Price
- $11.63
- Rating
- 4.7/5
- Reviews
- 5,057
- Age
- 6y ago

In The Swim Calcium Hardness Increaser for Swimming Pools - Fast-Acting Scale Prevention - 94% Calcium Chloride - 25 Pounds
- Price
- $56.66
- Rating
- 4.7/5
- Reviews
- 1,231
- Age
- 15y ago

HTH 67059 Swimming Pool Care Calcium Hardness Up Swimming Pool Chemical Protects Swimming Pool Surfaces and Liners 4 Lbs
- Price
- $9.38
- Rating
- 4.6/5
- Reviews
- 383
- Age
- 4y ago

Pool Mate 8-Pounds Premium Calcium Hardness Increaser for Pools 100% Calcium Chloride
- Price
- $19.05
- Rating
- 4.7/5
- Reviews
- 1,331
- Age
- 12y ago

Pool Mate 16-Pounds Premium Calcium Hardness Increaser for Pools 100% Calcium Chloride
- Price
- $31.49
- Rating
- 4.7/5
- Reviews
- 1,617
- Age
- 11y ago
Trending
estimated 90-day click momentum
Pool Mate 16-Pounds Premium Calcium Hardness Increaser for Pools 100% Calcium Chloride
- Price
- $31.49
- Rating
- 4.7/5
- Reviews
- 1,617
- Age
- 11y ago

Robelle 8-Pounds Premium Pool Calcium Up Calcium Hardness Increaser
- Price
- $15.60
- Rating
- 4.7/5
- Reviews
- 554
- Age
- 10y ago

HTH 67059 Swimming Pool Care Calcium Hardness Up Swimming Pool Chemical Protects Swimming Pool Surfaces and Liners 4 Lbs
- Price
- $9.38
- Rating
- 4.6/5
- Reviews
- 383
- Age
- 4y ago

Pool Mate 8-Pounds Premium Calcium Hardness Increaser for Pools 100% Calcium Chloride
- Price
- $19.05
- Rating
- 4.7/5
- Reviews
- 1,331
- Age
- 12y ago

MAV AquaDoc Pool Calcium Hardness Increaser - 5lb - Fast-Dissolving Calcium Chloride for Swimming Pools - Made in the USA
- Price
- $20.91
- Rating
- 4.8/5
- Reviews
- 125
- Age
- 1y ago
Newest
by launch date
MAV AquaDoc Pool Calcium Hardness Increaser - 5lb - Fast-Dissolving Calcium Chloride for Swimming Pools - Made in the USA
- Price
- $20.91
- Rating
- 4.8/5
- Reviews
- 125
- Age
- 1y ago

HTH 67059 Swimming Pool Care Calcium Hardness Up Swimming Pool Chemical Protects Swimming Pool Surfaces and Liners 4 Lbs
- Price
- $9.38
- Rating
- 4.6/5
- Reviews
- 383
- Age
- 4y ago

AquaDoc Spa Calcium Hardness Increaser Hot Tub Owners Rely on Calcium Increaser Spa Hardness Increaser & Calcium Booster for Hot Tubs
- Price
- $18.30
- Rating
- 4.7/5
- Reviews
- 712
- Age
- 5y ago

In The Swim Calcium Hardness Increaser for Swimming Pools - Fast-Acting Scale Prevention - 94% Calcium Chloride - 45 Pounds
- Price
- $80.18
- Rating
- 4.7/5
- Reviews
- 1,231
- Age
- 5y ago

Clorox Pool&Spa Swimming Pool Calcium Hardness Increaser Prevents Corrosion Etching and Staining 4LB (Pack of 1)
- Price
- $11.63
- Rating
- 4.7/5
- Reviews
- 5,057
- Age
- 6y ago
Competition
Competition: brands, sellers & click share
The top 5 products take an estimated 77% of clicks. A locked shelf that new listings rarely crack.
Brands
7 falling
Sellers
39
Est. top-5 brand share
94%
Top 20: 100%
Est. top-5 click share
77%
Top 20: 100%
Open market
3%
- CLOROX Pool&Spa29%
- Pool Mate24%
- In The Swim19%
- HTH14%
- Robelle7%
- MAV AquaDoc4%
- Open — no brand owns it (1 brand, 3%)
Demand
Calcium Hardness Increaser search demand
Weekly searches over the year, seasonality beneath. Pick a range.
Peak months: May, Jun, Jul · busiest ÷ quietest = 13.3×
Search terms
Top Calcium Hardness Increaser search terms shoppers use
The exact words shoppers type, with estimated yearly volume, growth, and conversion.
- calcium hardness increaser81K/yr
- pool calcium hardness increaser25K/yr
- calcium hardness increaser for swimming pools20K/yr
- pool hardness increaser17K/yr
- calcium chloride for pools13K/yr
- pool calcium13K/yr
- hardness increaser for swimming pools11K/yr
- calcium for pool7K/yr
- calcium increaser for pool7K/yr
- hardness plus for swimming pools5K/yr
Reviews and returns
What reviews say buyers love and hate about Calcium Hardness Increaser
We read the reviews and the return reasons for every product selling here.
“to large”
Every topic
Every topic buyers talk about, one row each.
Red shows the share of negative reviews and green the share of positive reviews, biggest topic first. Open a row to read what they wrote.
19 topics
Keep looking
Related niches
Niches in the same category that score near this one. Research these next.
Best Flapen score
The highest-scoring niches we track right now, across every category.
FAQ
Common Calcium Hardness Increaser questions
Answered from the same tracked data.
Figures on this page are estimates modeled from public Amazon pages and third-party keyword data. Amazon does not supply them, and no connected seller's data is used. How we handle Amazon data









