API Water Softener Pillow, Size 5

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About This Item

Details

  • Contains resins to remove calcium, magnesium and soluble heavy metal to soften water.
  • Ideal mineral levels are essential to the health and happiness of fish.
  • The convenient pouch is fully rechargeable and can be used multiple times.
  • Does not contain harmful chemicals, making this pouch completely safe for all freshwater fish.
  • Designed for tanks big and small—can be placed in aquariums up to 20 gallons.

Instructions

FAQ

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Questions & Answers

19 Customer Questions

Will this product lower carbonate hardness?

Is it safe to use a ph corrector when using water softener pillow? Also, can i use a regular filter at the same time I'm using the water softener pillow?

Answer by Chewy • Feb 06, 2020
As long as the Water Softener Pillow is in the water flow, removing any additional media should not be necessary. The Water Softener Pillow can potentially lower the pH, so we do recommend adding an appropriate buffer alongside this to keep the pH levels stable.

Where exactly do I place the pillow? Do I have to replace it with something that's already in the filter or do I just add it?

Answer by Chewy • Oct 13, 2022
The API Water Softener Pillow should be added in addition to other filter medias, not replacing any, unless it cannot otherwise physically fit into the filter. The Water Softener Pillow is removed when the target hardness level is achieved, so it is a temporary filter media. You will want all your other filter medias to stay because they are longer term medias that will accumulate much more beneficial bacteria on their surfaces and are crucial to keeping the nitrogen cycle happy and healthy within your aquarium system.

When the water reaches the level of softness and needs to be at, can I take it out?

Answer by Chewy • Sep 04, 2022
The water softener pillow can be used as needed, it does not have to be used all the time. It can be recharged and re-used up to 4 times. When not in use, store pouch in recharging solution; do not let pillow dry out. Replace when pillow ceases to function properly after recharging.
Reviews
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4.2
Rated 4.2 out of 5 stars
49 Ratings
Terms & Conditions

29 Customer Reviews

Rated 1 out of 5 stars
By Kristina on Dec 18, 2025

Didn’t help

Disappointed this product didn’t help. Tested water hardness before adding and tested after removing and the hardness levels didn’t change.

Disappointed this product didn’t help. Tested water hardness before adding and tested after removing and the hardness levels didn’t change.

Rated 5 out of 5 stars
By Dawn on Nov 29, 2025

Aquarium help

Even though we use R/O water in our aquarium, it still shows 'hard' when tested. This product helped push it into the 'soft' range.

Even though we use R/O water in our aquarium, it still shows 'hard' when tested. This product helped push it into the 'soft' range.

Rated 5 out of 5 stars
By Danielle on Nov 1, 2024

Effective

Slow release, works well, works multiple times with recharge. Great bang 4 yo buck

Slow release, works well, works multiple times with recharge. Great bang 4 yo buck

Rated 5 out of 5 stars
By Dawn on Nov 19, 2023

Something that works!

Originally my tank had soft water, but all of the sudden I had these nasty hard water spots and very high hardness. It works like a charm, and very quickly. I will

Originally my tank had soft water, but all of the sudden I had these nasty hard water spots and very high hardness. It works like a charm, and very quickly. I will say, Follow The Instructions! The first time I put them in there I was busy and forgot to take them out after 48 hours and the hardness spiked right back up to where it was.

Rated 5 out of 5 stars
By EuropaEpsilon on Nov 21, 2022

My neon tetras are thankful

I bought this water softener pillow because I realized my now tetras were nipping at each other while my cherry barbs were just fine. After being in my HOB filter

I bought this water softener pillow because I realized my now tetras were nipping at each other while my cherry barbs were just fine. After being in my HOB filter for 6hrs my tetras started swimming higher up the water column, they usually like to hang out at the bottom half. And their feeding has resumed to normal. It fit fine on my HOB filter and I still had plenty of space to add filter fiber.

Rated 4 out of 5 stars
By Obiewan on Sep 30, 2021

Works Great for smaller tanks

Works great for smaller tanks 10 and 20 gallon. Bigger tanks not so much just better to use RO water and add minerals for Large tanks

Works great for smaller tanks 10 and 20 gallon. Bigger tanks not so much just better to use RO water and add minerals for Large tanks

Rated 1 out of 5 stars
By snaillady on Jun 18, 2021

Massive Ph Drop!!

Worked to soften hard water very well, but at the cost of acidifying all of my tank water! Not worth it; hardness wasn’t hurting my fish but the low ph definitely

Worked to soften hard water very well, but at the cost of acidifying all of my tank water! Not worth it; hardness wasn’t hurting my fish but the low ph definitely is.

Rated 5 out of 5 stars
By Alma on May 18, 2021

Softens water for 10 gallon tank

I bought three of these pillows to alternate every two days before my weekly water changes. I’ve read about peat moss but I don’t like the tannins. I use one pouch

I bought three of these pillows to alternate every two days before my weekly water changes. I’ve read about peat moss but I don’t like the tannins. I use one pouch for my 10 gallon Betta tank. Before the pillow, my water hardness was at 16 dGH. With the pillow, my water hardness is at 9 dGH (yay!). The hard part is remembering to place them in their recharging solution when not in use, so I’ll have to order a replacement.

Rated 4 out of 5 stars
By Diana on May 21, 2021

Water softener pillow

API water softener pillows worked as advertised. Multiple pillows needed for large tanks.

API water softener pillows worked as advertised. Multiple pillows needed for large tanks.

Rated 5 out of 5 stars
By Jessie on Feb 26, 2021

Good solution

This was really easy to use and quickly brought my aquarium GH levels to the appropriate level.

This was really easy to use and quickly brought my aquarium GH levels to the appropriate level.