Resources and Articles

Resources

Check which fish are legal in your state before you order.

Gold-flecked red-bellied piranha swimming in dark water

Illegal Fish to Own in the US: Prohibited Aquarium Fish by State (2026)

Articles

Care guides, water chemistry and how we ship.

Close-up of green pothos leaves and stems growing in a tabletop aquarium

Pothos in Aquariums: Houseplants That Pull Nitrate, and the Mistakes to Avoid

Black ghost knifefish curving down through driftwood and green plants in a dark aquarium

Chloramine in Aquariums: What Your Water Conditioner Really Does

Barred green-gold severum among broad Anubias leaves in a planted aquarium

Nitrate Levels in Aquarium Water: Safe Targets and How to Keep Them Down

Orange-and-black oscar swimming past a textured rock wall

Nitrite Poisoning in Fish: Brown Blood Disease and How to Stop It

Slender silver-and-black duckbill shovelnose catfish swimming over sand in a bright turquoise aquarium

Ammonia in Fish Tank Water: Why pH Decides How Toxic It Is

Yellowjacket cichlid with dark blotches hovering over pale sand

The Aquarium Nitrogen Cycle: What Actually Does the Work

Large yellow-and-olive striped fahaka puffer resting on river pebbles in a home aquarium

Aquarium Temperature for Tropical Fish: Metabolism, Oxygen and Heat Waves

Maze-patterned sailfin pleco resting on colorful aquarium gravel

Spirulina for Fish: What It Does and Which Fish Benefit

Bright orange cichlid nosing toward white pebbles beside grey rock and driftwood

Does Color Enhancing Fish Food Work? What Astaxanthin Can and Can't Do

Blue-green spangled green terror cichlid with an orange-edged tail, surrounded by tiny fry in a planted home aquarium

Tap Water for Aquariums: What's in It and How to Read Your Water Report

Blue-and-white banded frontosa cichlid swimming over dark rockwork

GH vs KH: pH, Hardness and Buffering in Freshwater Aquariums

Two barred yellow peacock bass swimming together in a dark aquarium

Is It Safe to Buy Fish Online? What Happens Between the Seller's Tanks and Yours

Redtail catfish with a bright orange tail swimming across a long rock-backed aquarium

How Many Gallons Is My Tank? Finding True Water Volume for Dosing

Columns of fine bubbles rising through deep blue water

How Long Can Fish Survive in a Bag? The Science of Shipping Fish in Pure Oxygen

Popular posts

  1. Blue-green spangled green terror cichlid with an orange-edged tail, surrounded by tiny fry in a planted home aquarium
    Tap Water for Aquariums: What's in It and How to Read Your Water Report
  2. Two barred yellow peacock bass swimming together in a dark aquarium
    Is It Safe to Buy Fish Online? What Happens Between the Seller's Tanks and Yours
  3. Columns of fine bubbles rising through deep blue water
    How Long Can Fish Survive in a Bag? The Science of Shipping Fish in Pure Oxygen
  4. Redtail catfish with a bright orange tail swimming across a long rock-backed aquarium
    How Many Gallons Is My Tank? Finding True Water Volume for Dosing
  5. Blue-and-white banded frontosa cichlid swimming over dark rockwork
    GH vs KH: pH, Hardness and Buffering in Freshwater Aquariums