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
354
$8.45Chewy Price
($0.53/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.6/5
Excellent

Ease of Use

4.6/5
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, 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
306
$13.99Chewy Price
($0.42/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.5/5
Great

Ease of Use

4.7/5
Excellent

Effectiveness

4.7/5
Excellent

Long-Term Results

4.5/5
Great

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Freshwater, Saltwater

Fish Type

Tropical Freshwater, Marine Fish
3
Acurel F Aquarium Water Clarifier, 50-mL bottle

Acurel F Aquarium Water Clarifier, 50-mL bottle

Rated 4.6 out of 5 stars
106
$8.99Chewy Price
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.7/5
Excellent

Ease of Use

4.6/5
Excellent

Effectiveness

4.7/5
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, Betta, Cichlid, Goldfish
4
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
546
$10.99Chewy Price
($0.69/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.6/5
Excellent

Ease of Use

4.6/5
Excellent

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
5
CaribSea Eco-Complete Planted Aquarium Substrate, Black, 20-lb bag
CaribSea Eco-Complete Planted Aquarium Substrate, Black, 20-lb bag
CaribSea Eco-Complete Planted Aquarium Substrate, Black, 20-lb bag

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

Rated 4.4 out of 5 stars
105
$27.86Chewy Price
($1.40/lb)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.4/5
Great

Ease of Use

4.8/5
Excellent

Effectiveness

4.6/5
Excellent

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...
6
Fluval Plant & Shrimp Stratum Plant Care, 17.6-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 17.6-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 17.6-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 17.6-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 17.6-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 17.6-lb bag
Fluval Plant & Shrimp Stratum Plant Care, 17.6-lb bag

Fluval Plant & Shrimp Stratum Plant Care, 17.6-lb bag

Rated 4.6 out of 5 stars
77
$43.99Chewy Price
($2.50/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

4.5/5
Great

Long-Term Results

4.3/5
Great

Is this freshwater aquarium water treatment right for my pet?

Aquarium Type

Nano Tank, Freshwater

Fish Type

Tropical Freshwater, Betta, Cichlid, Goldfish
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
82
$19.99Chewy Price
($0.63/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
Aqueon Tap Water Conditioner, 16-fl oz bottle
Aqueon Tap Water Conditioner, 16-fl oz bottle
Aqueon Tap Water Conditioner, 16-fl oz bottle
Aqueon Tap Water Conditioner, 16-fl oz bottle
Aqueon Tap Water Conditioner, 16-fl oz bottle
Aqueon Tap Water Conditioner, 16-fl oz bottle
Aqueon Tap Water Conditioner, 16-fl oz bottle
Aqueon Tap Water Conditioner, 16-fl oz bottle
Aqueon Tap Water Conditioner, 16-fl oz bottle

Aqueon Tap Water Conditioner, 16-fl oz bottle

Rated 4.7 out of 5 stars
114
$10.95Chewy Price
($0.69/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.4/5
Great

Ease of Use

4.8/5
Excellent

Effectiveness

4.7/5
Excellent

Long-Term Results

4.8/5
Excellent

Is this freshwater aquarium water treatment right for my pet?

Top Ingredients

Sodium Thiosulfate, Disodium Edta, Sodium Carbonate, Polyvinylpyrollidones

Aquarium Type

Freshwater

Fish Type

Tropical Freshwater
9
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
34
$15.99Chewy Price
($1.00/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

4.8/5
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
10
Dr. Tim's Aquatics Ammonium Chloride Solution for Cycling Aquariums, 2-fl oz bottle
Dr. Tim's Aquatics Ammonium Chloride Solution for Cycling Aquariums, 2-fl oz bottle
Dr. Tim's Aquatics Ammonium Chloride Solution for Cycling Aquariums, 2-fl oz bottle
Dr. Tim's Aquatics Ammonium Chloride Solution for Cycling Aquariums, 2-fl oz bottle
Dr. Tim's Aquatics Ammonium Chloride Solution for Cycling Aquariums, 2-fl oz bottle
Dr. Tim's Aquatics Ammonium Chloride Solution for Cycling Aquariums, 2-fl oz bottle
Dr. Tim's Aquatics Ammonium Chloride Solution for Cycling Aquariums, 2-fl oz bottle

Dr. Tim's Aquatics Ammonium Chloride Solution for Cycling Aquariums, 2-fl oz bottle

Rated 4.7 out of 5 stars
50
$4.69Chewy Price
($2.35/fl oz)
Promo, New Customers Only: Spend $49+, Get $20 eGift Card

Our ratings

Compatibility

4.4/5
Great

Ease of Use

4.7/5
Excellent

Effectiveness

4.7/5
Excellent

Long-Term Results

4.7/5
Excellent

Is this freshwater aquarium water treatment right for my pet?

Top Ingredient

Ammonium chloride

Aquarium Type

Freshwater, Saltwater

Fish Type

Tropical Freshwater, Marine Fish, Cichlid, Marine Invertebrate...