Fish Tank Atlas

Best fish for beginners

Pick one starter set for your tank size and buy the whole group, not one of each. Every fish here is rated easy to keep by our sources and leaves other fish’s fins alone.

Before you buy anything: cycle the tank first, so the filter can handle fish waste. How to tell your tank is ready.

Starter sets

Each pair in a set gets a clean “yes” from our compatibility checks at that tank size, and our crowding model rates it light or moderate, so there’s room to settle in.

10-gallon tank

Guppies over panda corydoras

Colorful guppies near the top, a busy group of pandas on the sand. Both are sold at big pet stores, so you can buy the whole set in one trip. Guppies give birth to live young easily, so expect babies if you buy males and females.

From about $63 for the fish · All sold at PetSmart · Moderate stocking

Check this set in the compatibility checker →

A betta with bottom dwellers

One betta owns the surface while tiny pygmy corydoras school near the bottom, out of its way. The pygmies usually come from a fish store or online shop.

From about $40 for the fish · Some from fish stores or online · Moderate stocking

Check this set in the compatibility checker →

Neon tetras over pygmy corydoras

Two small schools in two layers: neons in the middle, pygmies near the sand. Both like soft, slightly acidic water.

From about $54 for the fish · Some from fish stores or online · Moderate stocking

Check this set in the compatibility checker →

20-gallon tank

Neon tetras over panda corydoras

The classic beginner community, with room to spare. Both are sold at big pet stores.

From about $72 for the fish · All sold at PetSmart · Light stocking

Check this set in the compatibility checker →

Platies with bronze corydoras

Hardy, cheap and easy to find. Platies like harder, alkaline water, and bronze corydoras handle it too. Platies give birth to live young easily, so expect babies if you buy males and females.

From about $59 for the fish · All sold at PetSmart · Moderate stocking

Check this set in the compatibility checker →

A betta community

A betta at the top, a school of tiny embers in the middle and pygmies near the bottom. The embers and pygmies usually come from a fish store or online shop.

From about $88 for the fish · Some from fish stores or online · Light stocking

Check this set in the compatibility checker →

The fish, one by one

Fits a 10-gallon tank

Betta fish (Betta splendens)Betta fishBuy 1 · 5 gal+ · Heater · Lives 3–5 years$4–20 eachEasy to find: sold at PetSmart⚠ One per tank: bettas fight their own kind.⚠ Eats shrimp, so no cherry shrimp with it.Ember tetra (Hyphessobrycon amandae)Ember tetraBuy 6+ · 10 gal+ · Heater · Lives 2–4 yearsAbout $36 for 6Harder to find: mostly fish stores and online shops⚠ Tiny, so keep it with other small, peaceful fish.Guppy (Poecilia reticulata)GuppyBuy 3+ · 10 gal+ · Heater · Lives 2–3 yearsAbout $15 for 3Easy to find: sold at PetSmart⚠ Gives birth to live young easily: expect babies if you keep males and females.⚠ Long fins: keep away from fin-nippers.Neon tetra (Paracheirodon innesi)Neon tetraBuy 6+ · 10 gal+ · Heater · Lives 5–8 yearsAbout $18 for 6Easy to find: sold at PetSmart⚠ Tiny, so keep it with other small, peaceful fish.Panda corydoras (Corydoras panda)Panda corydorasBuy 6+ · 10 gal+ · Heater optional · Lives 10–15 yearsAbout $48 for 6Easy to find: sold at PetSmartPygmy corydoras (Corydoras pygmaeus)Pygmy corydorasBuy 8+ · 10 gal+ · Heater · Lives 3–5 yearsAbout $36 for 8Harder to find: mostly fish stores and online shops⚠ Tiny, so keep it with other small, peaceful fish.

Needs 20 gallons or more

Bronze corydoras (Corydoras aeneus)Bronze corydorasBuy 5+ · 20 gal+ · Heater optional · Lives 10 yearsAbout $50 for 5Easy to find: sold at PetSmartPlaty (Xiphophorus maculatus)PlatyBuy 3+ · 20 gal+ · Heater optional · Lives 3–4 years$9–12 for 3Easy to find: sold at PetSmart⚠ Gives birth to live young easily: expect babies if you keep males and females.

Clean-up crew (optional)

Not fish, and not required. Add them once the tank is settled, if you want help with algae and leftovers.

Cherry shrimp (Neocaridina davidi)Cherry shrimpBuy 6+ · 5 gal+ · Heater optional · Lives 1–2 yearsAbout $30 for a pack of 10Harder to find: mostly fish stores and online shops⚠ Add only to a tank that has been running for a while, not straight after cycling.Zebra nerite snail (Vittina natalensis)Zebra nerite snailBuy 1 · 5 gal+ · Heater optional · Lives 2–3 yearsAbout $4 eachEasy to find: sold at PetSmart⚠ Add only to a tank that has been running for a while, not straight after cycling.

Why not these?

We add species every week; more beginner favorites are on the way.

Where the prices come from

Each price is what the store’s own website listed on November 6, 2026. PetSmart sells live fish in store only, and prices vary by location, so treat these as a guide. “Sold at PetSmart” means PetSmart’s US website lists it; other chains and local fish stores may carry it too.