Profiles with adult-minded tank sizes, temperament, and FAQs. Filters are ordinary links so you can share a freshwater or beginner view.
Showing 10 species
Freshwater · Beginner
Betta splendens
Bettas are labyrinth fish that breathe from the surface, but they still need a heated, filtered aquarium — not a vase. A 5-gallon tank is a practical minimum for a single male.
Min. tank: 5 gal
Care notes →
Freshwater · Beginner
Paracheirodon innesi
Neon tetras are small Amazonian schoolers that look their best in a planted 10-gallon (or larger) tank with a proper group, dimmer light, and stable, clean water.
Min. tank: 10 gal
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Freshwater · Beginner
Poecilia reticulata
Guppies are colorful, active livebearers for a heated 10-gallon (or larger) community — with one caveat: mixed sexes will produce fry, often lots of them.
Min. tank: 10 gal
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Freshwater · Intermediate
Carassius auratus
Goldfish are coldwater carp, not bowl ornaments. Fancy strains need tens of gallons and strong filtration; single-tail commons belong in very large tanks or ponds.
Min. tank: 30 gal
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Freshwater · Intermediate
Pterophyllum scalare
Freshwater angelfish are tall Amazonian cichlids. They need height more than a long, low tank — about 30 gallons and 18+ inches of height for a pair is a practical indoor start.
Min. tank: 30 gal
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Freshwater · Beginner
Corydoras paleatus
Peppered corydoras are social, sandy-bottom catfish. Keep a group of six or more in a 20-gallon tank with sand, not gravel that can nick their barbels.
Min. tank: 20 gal
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Freshwater · Advanced
Astronotus ocellatus
Oscars are large, messy cichlids for dedicated tanks. One adult needs about 75 gallons as a conservative minimum, powerful filtration, and an owner ready for digging, waste, and a long-lived pet.
Min. tank: 75 gal
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Saltwater · Intermediate
Amphiprion ocellaris
Ocellaris clownfish are among the more forgiving marine fish — but they still need a cycled saltwater tank, stable salinity, and marine-level testing. A 20-gallon tank can house a pair; 30 gallons is more comfortable.
Min. tank: 20 gal
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Saltwater · Intermediate
Zebrasoma flavescens
Yellow tangs are active Hawaiian surgeonfish that need swimming room, not a nano reef. A conservative home-aquarium minimum is about 125 gallons with length to patrol and rock to graze.
Min. tank: 125 gal
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Saltwater · Intermediate
Nemateleotris magnifica
Firefish gobies are elegant, hovering dartfish for a covered saltwater tank. A 20-gallon reef can work for one; the lid is not optional — they jump.
Min. tank: 20 gal
Care notes →