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API

API WATER SOFTENER PILLOW Aquarium Canister Filter Filtration Pouch 1-Count Bag

  • Based on 3,481 reviews
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Availability: In Stock.
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Arrives Tuesday, Oct 13
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Features

  • Contains one (1) API WATER SOFTENER PILLOW Aquarium Canister Filter Filtration Pouch 1-Count Bag
  • Softens hard water
  • Reduces general hardness by lowering calcium and magnesium
  • Easy-to-use pre-dosed pouch fits most canister filters on the market for freshwater aquariums
  • Use when starting or maintaining an aquarium when testing indicates hardness above the desired level, can be reused after it is recharged

Description

API WATER SOFTENER PILLOW Aquarium Canister Filter Filtration Pouch is a chemical filtration media that reduces general hardness found in tap water for aquarium use. WATER SOFTENER PILLOW works to lower calcium and magnesium levels, and also removes heavy metals and reduces white, crusty mineral deposits on aquarium surfaces. WATER SOFTENER PILLOW can be reused after it is recharged in a salt solution. Use when starting or maintaining an aquarium when testing indicates water hardness above the desired level. Use according to directions on product packaging. With API Aquarium products, it’s easy to keep a beautiful saltwater, freshwater or reef aquarium. For over 50 years, API has been creating innovative, research-driven solutions that make it easier to care for your fish and aquarium. API Aquarium Treatment Supplies are designed to work in conjunction with each other to provide best results to control algae, promote healthy bacterial growth and help control and cure fish diseases and conditions such as ich and fin rot. They work to provide a safe, hospitable environment for fish such as tropical community fish, cichlids, goldfish and more. With API, you can spend more time admiring your fish, and less time scrubbing your tank. Make sure to use all products as directed in order to ensure the best results.

Brand: API


Item Weight: 23 g


Item Form: Granules


Number of Packs: 1


Unit Count: 1 Count


Product Dimensions ‏ : ‎ 4.5 x 1 x 7.38 inches; 0.81 ounces


Item model number ‏ : ‎ 49A


Department ‏ : ‎ Unisex-Adult


Date First Available ‏ : ‎ June 15, 2004


Manufacturer ‏ : ‎ Mars Fishcare


Best Sellers Rank: #13,739 in Pet Supplies (See Top 100 in Pet Supplies) #85 in Aquarium Filter Accessories


#85 in Aquarium Filter Accessories:


Customer Reviews: 4.2 4.2 out of 5 stars (3,481)


Brand Name: API


Number of Packs: 1


Unit Count: 1 Count


Manufacturer: Mars Fishcare


UPC: 317163001493


Number of Items: 1


Global Trade Identification Number: 93


Included Components: 16 Oz Bottle Of Algaway 5.4 Algaecide


Item Type Name: Aquarium Filtration Media


Model Number: 49A


Manufacturer Part Number: 49A


Item Weight: 23 g


Item Form: Granules


Pet Type: Fish


Target Species: Fish


Allergen Information: Apple Free


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Oct 13

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • Great
Got my hardness down for rams
Reviewed in the United States on September 8, 2026 by Carissa Farmer

  • OMG, this really worked.
This pillow really did a shockingly excellent job lowering the GH of my aquarium. My GH reduced from 18 to 4 dGH after 24 hours in my filter. Amazing, huh! The results lasted for about a month. After that, the GH slowly rises until the pillow is recharged. After about 8 weeks of use my GH is about 11-12 dGH without a recharge. Results may vary for larger tanks. I have this in a 10 gallon aquarium. ... show more
Reviewed in the United States on June 14, 2026 by P. Kelsey

  • Ok so far
I wasn’t expecting it to look the way it does. Instructions on back are confusing and I’m still not even sure if installing it correctly in the fish tank. I don’t think I’d buy again unless it somehow really changes the water.
Reviewed in the United States on August 24, 2024 by Aimee

  • It works!
Soften my extremely hard water enough for my electric blue rams.
Reviewed in the United States on July 15, 2026 by Ashley

  • Not too sure what to think
I have used this same item years ago and always got results. The description says that one pillow is good for up to a 20 gal tank... OK, that seems about right, and, it left me a little concerned as I was going to be using these pillows in 2.5 and 5 gal tanks. I placed one of the pillows in each tank planning to monitor them closely. After the 3rd or 4th hourly test without seeing any change in the parameters at all I decided that they were going to work slowly regardless the size. I tested at 24 hours... No change... and finally at 48 hours (which was 10 hours ago) I tested the two tanks and neither tank showed any change at all. I don't know what to think... I mean I assumed that these came needing to be charged but the package says ready to use. So, as I said, I have used these quite often over the years... This is my first time using them since they are being sold dry rather than sold in a jar of charging fluid. I am going to charge these two pillows and try them again just in case my logic that says they should be charged before use is correct. I am not expecting the outcome to be any different than this time was, but I will post in comments should it be so. ... show more
Reviewed in the United States on March 9, 2020 by Brian

  • Use these
This stuff actually worked. I’ve been plagued by hard water ever since moving to my current home twelve years ago. My aquarium equipment has always gathered white buildup no matter how many softeners I tried. UNTIL this one! Absolutely zero buildup has stuck since I added one of these packs to my tank! I am so thrilled. Everyone in the tank seems happy and healthy and I’ve been using these for about a year now. Water clarity is crystal as always. ... show more
Reviewed in the United States on October 21, 2025 by Chloe

  • It works
It works. Depending on the size of your aquarium, and the hardness of your water, it might not get all the way in one use. That's fine, it's reusable. MAKE SURE TO READ THE STORAGE/ RECHARGE INSTRUCTIONS. I keep the instructions rubber-banded to the bottle I store it in.
Reviewed in the United States on May 19, 2026 by nathan

  • It really depends on what your water level is
It is not clear whether this works or not because I’ve put 2 into my tank filter system but it didn’t change the water hardness. I wish there was another way to reduce the hardness of the water. Unfortunately I’m disabled and all I have is water thru my faucet which is very hard. Does anyone know what else I can do ... show more
Reviewed in the United States on June 17, 2026 by Amazon Customer

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