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Marine & Freshwater

(37 results)
Seachem® Prime® Aquarium Water Conditioner Chlorine & Ammonia Detoxifier
4 sizes
(385)
$3.19
$6.99
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Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Stability® New Tank Stabilization System Aquarium Water Conditioner
2 sizes
(214)
$4.99
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Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Purigen® Premium Synthetic Absorbent - Aquarium Filter Media
2 sizes
(68)
$9.89
$12.99
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+ 1 more
Seachem® Prime® Chlorine & Ammonia Detoxifier
2 sizes
(11)
$52.99
$105.09
Options from
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Stability® for Aquarium Cycling
2 sizes
(8)
$48.11
$96.69
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Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Flourish Excel™ for Live Aquarium Plants
2 sizes
(14)
$10.79
$17.99
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+ 1 more
Seachem® Matrix™ - Aquarium Filter Media
3 sizes
(20)
$7.99
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+ 1 more
Seachem® Flourish Potassium™ for Live Aquarium Plants
(6)
$11.39
$11.89
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+ 1 more
Seachem® Purigen® Aquarium Water Treatment
(10)
$57.19
$115.31
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Flourish® Freshwater Aquarium Comprehensive Plant Supplement
2 sizes
(55)
$7.99
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Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Alert Combo™ Aquarium pH & Ammonia Detector for Aquarium Water Testing
(80)
$9.54
$18.99
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Reef Strontium™ for Reef Aquarium Water Care
(0)
$7.03
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Reef Iodide™ for Reef Aquarium Water Care
2 sizes
(0)
$7.09
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+ 1 more
Seachem® Reef Advantage Magnesium™ for Reef Aquarium Water Care
2 sizes
(0)
$6.09
Options from
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Reef Plus™ for Reef Aquarium Water Care
2 sizes
(0)
$7.24
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Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Reef Buffer™ for Reef Aquarium Water Care
2 sizes
(0)
$7.19
Options from
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Reef Fusion 2™ for Reef Aquarium Water Care
2 sizes
(0)
$8.49
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+ 1 more
Seachem® Reef Fusion 1™ for Reef Aquarium Water Care
2 sizes
(0)
$8.49
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+ 1 more
Seachem® Reef Status Calcium Kit for Reef Aquarium Water Care
(0)
$34.22
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Reef Carbonate™ for Reef Aquarium Water Care
2 sizes
(0)
$4.59
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SeaChem Reef Complete Marine Care for Reef Aquarium Water Care
(0)
$7.03
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Clarity™ for Saltwater Aquariums
(18)
$5.99
$14.99
Online Only! Save 20% on your purchase with code SAVE20
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+ 1 more
Seachem® Flourish® for Live Aquarium Plants
(4)
$36.14
$72.86
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Phosguard™ Aquarium Water Treatment
2 sizes
(7)
$32.30
$65.10
Options from
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Tidal™ 75 Zeolite Filter Pouch - Aquarium Media
(0)
$8.19
Save 40% On First Autoship Order of Aquatic Filter Media
Buy Any Aquatic Filter and Get 20% Off All Aquatic Media
Seachem® Tidal™ 110 MatrixCarbon - Aquarium Filter Media
(0)
$13.29
Online Only! Save 20% on your purchase with code SAVE20
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+ 1 more
Seachem® Tidal™ 75 Matrix Carbon - Aquarium Filter Media
(0)
$10.13
$20.49
Save 40% On First Autoship Order of Aquatic Filter Media
Buy Any Aquatic Filter and Get 20% Off All Aquatic Media
Seachem® Tidal Matrix™ - Internal Fish Tank Filter
(0)
$7.63
$15.39
Buy Any Aquatic Filter and Get 20% Off All Aquatic Media
Seachem® Tidal Matrix™ - Internal Fish Tank Filter
(2)
$6.98
$14.09
Buy Any Aquatic Filter and Get 20% Off All Aquatic Media
Seachem® Tidal ™ - Replacement Aquarium Filter Media for Fish Tanks
(0)
$11.99
$16.89
Online Only! Save 20% on your purchase with code SAVE20
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+ 1 more
Seachem® Tidal ™ - Replacement Aquarium Filter Media for Fish Tanks
(0)
$10.99
$13.69
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Save 40% On First Autoship Order of Aquatic Filter Media
+ 1 more
Seachem® Tidal ™ - Replacement Aquarium Filter Media for Fish Tanks
(0)
$9.49
$11.09
Online Only! Save 20% on your purchase with code SAVE20
Save 40% On First Autoship Order of Aquatic Filter Media
+ 1 more
Seachem® Marine Buffer™ for Reef Aquarium Water Care
(0)
$27.59
$42.39
Online Only! Save 20% on your purchase with code SAVE20
Save 40% On First Autoship Order of Aquatic Watercare
+ 1 more
Seachem® Reef Complete™ Aquarium Water Treatment
(0)
$10.27
$20.70
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Tidal™ Zeolite - Aquarium Filter Media
(0)
$16.39
$18.79
Online Only! Save 20% on your purchase with code SAVE20
Save 40% On First Autoship Order of Aquatic Filter Media
+ 1 more
Seachem® Marine Buffer
(2)
$9.99
Save 40% On First Autoship Order of Aquatic Watercare
Buy 1 Get the 2nd 25% OFF on ALL Aquatic Food & Watercare! Excludes Top Fin® pre-conditioned water.
Seachem® Neutral Regulator Aquarium pH Water Conditioner for Aquarium pH Control
(6)
$7.29
Online Only! Save 20% on your purchase with code SAVE20
Save 40% On First Autoship Order of Aquatic Watercare
+ 1 more
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Explore Our Extensive Range of Fish Supplies 

At PetSmart, we offer a comprehensive selection of supplies for both freshwater and marine fish enthusiasts. Whether you're setting up a new aquarium or maintaining an existing one, our range of products ensures your aquatic pets thrive. From aquarium decor to essential maintenance tools, find everything you need to create a vibrant underwater world. 

Freshwater and Marine Fish Supplies 

Our collection includes a variety of aquarium accessories and pet fish supplies designed to cater to the unique needs of both freshwater and marine environments. Explore our selection of aquarium decor to enhance the beauty of your tank, and discover top-quality marine aquarium supplies to support the health of your aquatic life. 

Essential Aquarium Maintenance 

Maintaining a healthy aquarium requires the right tools and knowledge. Our range of aquarium maintenance products includes everything from filters to water conditioners, ensuring your tank remains a safe and clean environment for your fish. Learn how to maintain pH levels and keep your aquarium filter running efficiently with our expert tips. 

Frequently Asked Questions (FAQs) 

What maintenance does a fish tank need? 
Regular maintenance is crucial for a healthy aquarium. This includes cleaning the tank, changing the water, and checking the filter and pH levels. 
Can I put tap water in my fish tank? 
Tap water can be used in your fish tank, but it should be treated with a water conditioner to remove harmful chemicals like chlorine. 
Should an aquarium filter be on all the time? 
Yes, an aquarium filter should run continuously to maintain water quality and provide a healthy environment for your fish. 
How to maintain pH level in an aquarium? 
To maintain the pH level in your aquarium, regularly test the water and use pH adjusters as needed. Consistent water changes also help stabilize pH levels.