10 Best Freshwater Aquarium Water Treatments 2025: According to Reviews | Chewy

The 10 Best Freshwater Aquarium Water Treatments

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How we created this freshwater aquarium water treatment list

We leveraged input from our veterinarians and artificial intelligence to identify key considerations to help you find the best freshwater aquarium water treatment.
We scanned thousands of customer reviews and ratings and scored each product based on its performance against each of the key considerations. We then considered how popular a product is with Chewy customers and combined that with its key consideration scores to create the list of the best freshwater aquarium water treatments.

Key freshwater aquarium water treatment considerations

Compatibility

Ease of Use

Effectiveness

Long-Term Results

1
API Tap Water Conditioner, 16-fl oz bottle
API Tap Water Conditioner, 16-fl oz bottle
API Tap Water Conditioner, 16-fl oz bottle
API Tap Water Conditioner, 16-fl oz bottle
API Tap Water Conditioner, 16-fl oz bottle
API Tap Water Conditioner, 16-fl oz bottle

API Tap Water Conditioner, 16-fl oz bottle

Rated 4.8 out of 5 stars
376
$6.45Chewy Price
($0.41/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.5/5
Great

Ease of Use

4.6/5
Excellent

Effectiveness

4.7/5
Excellent

Long-Term Results

4.6/5
Excellent

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Freshwater, Saltwater

Fish Type

Tropical Freshwater, Cichlid, Betta, Goldfish...
2
Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle
Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle
Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle
Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle
Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle
Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle
Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle
Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle
Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle

Tetra AquaSafe Plus Freshwater & Marine Aquarium Water Conditioner, 33.8-fl oz bottle

Rated 4.8 out of 5 stars
324
$21.79Chewy Price
($0.65/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.6/5
Excellent

Ease of Use

4.7/5
Excellent

Effectiveness

4.7/5
Excellent

Long-Term Results

4.6/5
Excellent

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Freshwater, Saltwater

Fish Type

Tropical Freshwater, Marine Fish
3
API Stress Coat Aquarium Water Conditioner, 16-fl oz bottle
API Stress Coat Aquarium Water Conditioner, 16-fl oz bottle
API Stress Coat Aquarium Water Conditioner, 16-fl oz bottle
API Stress Coat Aquarium Water Conditioner, 16-fl oz bottle
API Stress Coat Aquarium Water Conditioner, 16-fl oz bottle
API Stress Coat Aquarium Water Conditioner, 16-fl oz bottle

API Stress Coat Aquarium Water Conditioner, 16-fl oz bottle

Rated 4.8 out of 5 stars
598
$10.99Chewy Price
($0.69/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.5/5
Great

Ease of Use

4.5/5
Great

Effectiveness

4.6/5
Excellent

Long-Term Results

4.6/5
Excellent

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Freshwater, Saltwater

Fish Type

Tropical Freshwater, Betta, Cichlid, Goldfish...

Health Feature

Anti-Fungal / Anti-Bacterial
4
Acurel F Aquarium Water Clarifier, 50-mL bottle

Acurel F Aquarium Water Clarifier, 50-mL bottle

Rated 4.6 out of 5 stars
116
$8.99Chewy Price
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.7/5
Excellent

Ease of Use

4.5/5
Great

Effectiveness

4.5/5
Great

Long-Term Results

4.5/5
Great

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Freshwater

Fish Type

Tropical Freshwater, Betta, Cichlid, Goldfish
5
Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag

Fluval Plant & Shrimp Stratum Plant Care, 4.4-lb bag

Rated 4.6 out of 5 stars
88
$15.29Chewy Price
($3.48/lb)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.2/5
Great

Ease of Use

4.5/5
Great

Effectiveness

4.6/5
Excellent

Long-Term Results

4.4/5
Great

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Nano Tank, Freshwater

Fish Type

Freshwater Invertebrate, Tropical Freshwater
6
Fritz Complete Full-Spectrum Aquarium Water Conditioner, 16-fl oz bottle

Fritz Complete Full-Spectrum Aquarium Water Conditioner, 16-fl oz bottle

Rated 4.9 out of 5 stars
38
$13.59Chewy Price
($0.85/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.8/5
Excellent

Ease of Use

4.8/5
Excellent

Effectiveness

4.9/5
Excellent

Long-Term Results

4.8/5
Excellent

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Freshwater, Saltwater

Fish Type

Tropical Freshwater, Marine Fish
7
Fritz Aquatics Fritz Zyme 7 Freshwater Nitrifying Bacteria for Aquariums, 32-fl oz bottle

Fritz Aquatics Fritz Zyme 7 Freshwater Nitrifying Bacteria for Aquariums, 32-fl oz bottle

Rated 4.6 out of 5 stars
94
$15.99Chewy Price
($0.50/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.3/5
Great

Ease of Use

4.6/5
Excellent

Effectiveness

4.4/5
Great

Long-Term Results

4.5/5
Great

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Freshwater

Fish Type

Tropical Freshwater

Health Feature

Anti-Fungal / Anti-Bacterial
8
CaribSea Eco-Complete Planted Aquarium Substrate, Red, 20-lb bag
CaribSea Eco-Complete Planted Aquarium Substrate, Red, 20-lb bag
CaribSea Eco-Complete Planted Aquarium Substrate, Red, 20-lb bag

CaribSea Eco-Complete Planted Aquarium Substrate, Red, 20-lb bag

Rated 4.4 out of 5 stars
114
$27.86Chewy Price
($1.40/lb)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.3/5
Great

Ease of Use

4.7/5
Excellent

Effectiveness

4.5/5
Great

Long-Term Results

4.8/5
Excellent

Is this freshwater aquarium water treatment right for my pet?

Material

Stone

Aquarium Type

Freshwater, Saltwater

Fish Type

Goldfish, Tropical Freshwater, Betta, Bottom Feeder...
9
SunGrow Betta Fish Indian Almond Leaves, Water Conditioner & Tank Treatment for Freshwater Aquarium
SunGrow Betta Fish Indian Almond Leaves, Water Conditioner & Tank Treatment for Freshwater Aquarium
SunGrow Betta Fish Indian Almond Leaves, Water Conditioner & Tank Treatment for Freshwater Aquarium
SunGrow Betta Fish Indian Almond Leaves, Water Conditioner & Tank Treatment for Freshwater Aquarium
SunGrow Betta Fish Indian Almond Leaves, Water Conditioner & Tank Treatment for Freshwater Aquarium
SunGrow Betta Fish Indian Almond Leaves, Water Conditioner & Tank Treatment for Freshwater Aquarium

SunGrow Betta Fish Indian Almond Leaves, Water Conditioner & Tank Treatment for Freshwater Aquarium

Rated 4.4 out of 5 stars
120
$4.97Chewy Price
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.6/5
Excellent

Ease of Use

4.5/5
Great

Effectiveness

4.4/5
Great

Long-Term Results

4.5/5
Great

Is this freshwater aquarium water treatment right for my pet?

Material

Plant Material

Aquarium Type

Freshwater, Saltwater

Fish Type

Betta, Goldfish, Cichlid, Tropical Freshwater...

Health Feature

Anti-Fungal / Anti-Bacterial, Reproduction & Nursing
10
API Freshwater Aquarium Master Test Kit, 800 count
API Freshwater Aquarium Master Test Kit, 800 count
API Freshwater Aquarium Master Test Kit, 800 count
API Freshwater Aquarium Master Test Kit, 800 count
API Freshwater Aquarium Master Test Kit, 800 count
API Freshwater Aquarium Master Test Kit, 800 count
API Freshwater Aquarium Master Test Kit, 800 count

API Freshwater Aquarium Master Test Kit, 800 count

Rated 4.7 out of 5 stars
264
$28.79Chewy Price
($0.04/ea)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.9/5
Excellent

Ease of Use

4.8/5
Excellent

Effectiveness

4.8/5
Excellent

Long-Term Results

4.7/5
Excellent

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Freshwater

Fish Type

Tropical Freshwater, Cichlid, Goldfish, Betta...