.JPG){kind=link}
Freshwater · Beginner
Betta
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 minimum for a single male.
Min. tank: 5 gal
Care notes →
Photo: Andrew Sheedy · CC BY-SA 4.0
Freshwater · Beginner · 10+ gal
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.
| Water type | Freshwater |
|---|---|
| Care level | Beginner |
| Minimum tank | 10 gallons |
| Temperament | Peaceful livebearer. Males may harass females if the ratio is poor. Fancy long-finned males can be nipped by barbs and some tetras. |
| Diet | Omnivore with a plant component. Quality flakes or micro pellets, plus blanched vegetables and occasional frozen foods. A varied diet supports color and fry production. |
| Temperature | 74–82 °F |
| pH | 6.8–7.8 |
| Hardness / salinity | Moderately hard to hard water suits them (around 8–20 dGH). Very soft, acidic water is a poorer match than for Amazonian tetras. |
Easy fish, busy tank
Poecilia reticulata is one of the most available beginner fish, and with good reason: they tolerate a range of conditions, show bright colors, and stay small. A 10-gallon tank is a minimum for a small group. Twenty gallons is more comfortable if you keep both sexes.
They need a heater in most homes, a filter, and regular water changes. Hardy does not mean bowl fish.
Breeding is the default
Guppies are livebearers. If you keep males and females together, you will get fry. A single female can store sperm and drop several broods. If you do not want a population boom, keep males only, or be ready to rehome fish and increase maintenance.
A common guideline is two or more females per male to reduce harassment. Dense plants give fry a chance if you want some to survive; most community tanks will eat many of them.
Fancy strains and health
Show strains with huge tails are less athletic than wild-type guppies and may be more prone to fin issues. Buy from a source that does not keep them in filthy cups, and quarantine if you can.
They appreciate moderately hard, alkaline water. If your tap is very soft, a buffering substrate or mineral additive used carefully can help.
Tank mates
- Other peaceful livebearers
- Corydoras and small peaceful tetras if water is not too soft
- Snails
- Avoid large cichlids, aggressive barbs, and fin-nippers
Gear for this fish
A few listings we would open for this species. Skip anything you already own that still works.
Aqueon Adjustable Pro heater, 50W
Guppies are tropical livebearers. Room temperature in most houses is not the mid-70s to low 80s F they want. 50W covers a 10-gallon without cooking it.
Use the 100W Pro in a 20-gallon. Skip a heater only if you actually measure 76 F in winter. A lid matters as much as heat — they jump.
See this listingTetraMin Tropical Flakes, 7.06 oz
Guppies are omnivores with a plant component. A basic flake they finish in a minute is the usual staple, plus veg and an occasional frozen food.
Do not pour a blizzard. Mixed sexes will add fry and bioload fast; leftover flake on the gravel is how tanks crash. Skip this if you already feed a quality micro pellet they eat.
See this listingA tight lid that actually fits the tank
Guppies jump. Fancy males especially. A glass canopy or mesh cover with no gaps around the filter is cheaper than replacing fish.
Lids are sized to the footprint, not the gallon number. Measure the opening. Skip a new lid if the kit hood already sits tight with the filter in place.
See this listing
Frequently asked questions
How many guppies in a 10-gallon tank?+
A small group, for example three to five, is reasonable if filtration and water changes are consistent. Mixed sexes will add fry and bioload quickly.
Will guppies overpopulate my tank?+
Yes, if you keep both sexes. Plan on males only, a species-only breeding setup, or a willingness to rehome.
Do guppies need a heater?+
In most indoor rooms, yes. They are tropical livebearers and do best in the mid-70s to low 80s F.
Related species
Freshwater · Beginner
Neon tetra
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
Care notes →
Freshwater · Beginner
Peppered cory
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 →