
Freshwater · Beginner
Guppy
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
Care notes →
Photo: ivabalk · CC0
Freshwater · Beginner · 5+ gal
Betta splendens
By Fishy Dave
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 minimum for a single male.
| Water type | Freshwater |
|---|---|
| Care level | Beginner |
| Minimum tank | 5 gallons |
| Temperament | Males are territorial with other male bettas and may nip long-finned tank mates. Females can live in carefully managed groups; males are usually best kept singly. |
| Diet | Carnivorous. High-quality betta pellets as a staple, supplemented with frozen or live brine shrimp, daphnia, and bloodworms. Feed small portions once or twice daily; skip a day occasionally. |
| Temperature | 76–82 °F |
| pH | 6.5–7.5 |
| Hardness / salinity | Soft to moderately hard (around 5–20 dGH). Stable, clean water matters more than chasing a perfect number. |
Betta splendens is often sold with a tiny cup, bowl, or unheated vase. That is marketing, not husbandry. These fish evolved in warm, vegetated waters in Southeast Asia. In the home they do best in a fully cycled aquarium with a heater, gentle filtration, and a lid.
A 5-gallon tank is a minimum for one male, and the guide to keeping a betta in a 5-gallon tank covers the heater, filter, and the one snail that fits with him. Ten gallons is easier to keep stable and gives more swimming room for long-finned strains. Bare, unheated containers swing in temperature and foul quickly. If you like the one-fish-tank idea, a pea puffer is another small-tank species pick, but it can't share a tank with a betta.
Use a heater set in the mid-to-upper 70s °F. Bettas become lethargic and prone to disease in cool rooms. Choose a filter with a gentle outflow. Sponge filters and baffled hang-on-back filters are popular, because long fins do not handle a blast of current well.
Provide resting spots near the surface (broad leaves, betta hammocks, or floating plants) and cover so they feel secure. Silk or live plants are kinder than sharp plastic décor that can tear fins. They are jumpers; keep a tight lid with space at the surface to gulp air.
Cycle the tank before adding the fish. Weekly water changes of about 25–40%, vacuuming debris, and testing ammonia, nitrite, and nitrate will catch problems early. Bettas tolerate a range of pH, but they do not tolerate ammonia.
Condition tap water to remove chlorine or chloramine. If you keep the tank planted, moderate lighting and a simple fertilizer routine are enough. Skip intense reef-style lighting.
Watch for clamped fins, lethargy, loss of appetite, white fungus-like patches, or bloating. Many issues trace back to cold water, dirty water, or overfeeding. Fin rot is common in poorly kept cups and bowls; it is far less common in a warm, clean aquarium.
Do not add aquarium salt as a default. Use medication only when you have a reason, and never mix random treatments. Quarantine new plants and tank mates when you can.
A few listings we would open for this species. Skip anything you already own that still works.
Aqueon Adjustable Pro heater, 50W
Bettas are tropical. A 5-gallon on a desk in an air-conditioned room drops into the 60s. This is the small size in the same Pro line we use on the 20-gallon kit notes. Still put a thermometer on the glass.
Skip a second heater if the tank already holds 76–80 F. 50W is plenty for 5–10 gallons. Two heaters fighting is how small tanks cook.
See this listinghygger sponge filter, small
Long fins do not like a hang-on-back blasting across a 5-gallon. An air-driven sponge is gentle and keeps the surface moving so they can still gulp air.
Air pump and tubing are not in the box. Squeeze the sponge so it sinks. Skip this if you already run a baffled hang-on-back. Hide it behind plants in a 5-gallon.
See this listingFluval Bug Bites Betta Formula, 1.05 oz
Bettas are insect eaters. Black soldier fly larvae as the first ingredient is closer to that than a generic flake. Micro granules are easy to count so you do not overfeed.
A pinch twice a day is plenty. Skip a day once a week. Frozen brine or daphnia still belong in the rotation. This is not a bowl-food workaround. The tank still needs heat and filtration.
See this listingA bowl is a poor home. There is usually no heater, no filter, and too little water to stay stable. Plan on at least 5 gallons, heated and filtered.
Yes in almost every home. They are tropical fish. Room-temperature tanks in air-conditioned houses are often too cold.
No. Males are famously territorial and will fight, often to serious injury. That is the origin of the 'Siamese fighting fish' name.
They can be, if you give them a cycled, heated 5-gallon (or larger) tank and do not treat them as a desk ornament. The fish is hardy; the typical retail setup is not.
Next step
Plan on 5 gallons or more. Put your actual tank size into the stocking calculator and it shows what else can live alongside them.
Open the stocking calculatorBefore you buy
Keep your fishies swimming.

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
Care notes →
Freshwater · Beginner
Paracheirodon innesi
Keep neon tetras in a school of at least 6, and plan on 8 to 12 in a 20-gallon tank. Adults stay under 1.5 inches. A 10-gallon is the minimum for a small school. Hold the water at 72 to 78°F, soft and slightly acidic (pH 5.5 to 7.0), with plants and dim light.
Min. tank: 10 gal
Care notes →
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
Care notes →