Should I buy it?
Guppy
Poecilia reticulata
Also known as: fancy guppy, guppy (endler crosses common)
Hardy and beginner-friendly in tap water. The real planning question is breeding. A mixed-sex group produces dozens of fry per month and overstocks a small tank within one season.
Guppy tank mates · 40L tank size hub
peaceful · beginner care
Sources & confidencehigh · verified · beginner: excellent
Checked against several solid care sources that mostly agree. Numbers here are a careful starting point. Your tap water, tank size, and habits decide the rest. How we evaluate.
Best for: First-time keepers in a hard-water community tank with a plan for the next two generations of fry.
Avoid if: You want a single colourful fish, cannot rehome fry, or already keep aggressive or fin-nipping species.
Common mistakeIgnoring sex ratios is the guppy mistake that turns a pretty starter tank into shredded females and a fry flood. One male with multiple females reduces harassment; several males with one female does the opposite. Plan the ratio and a backup plan for young before you buy the first bag. Colour morphs do not override basic livebearer maths.
Top things that go wrong
- Shrimp & snails. Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
What most shops don't tell you
- 1.Guppies are sold as the ultimate beginner fish that simply work. They are hardy in stable hard water, yet fancy strains still fail in cold, dirty, or male-heavy tanks, and the breeding rate is not optional. The shop display is a managed population. Home ownership without a fry plan is how people quit the hobby annoyed at a fish that did exactly what livebearers do.
- 2.Ignoring sex ratios in mixed tanks. A single male to multiple females reduces harassment and unplanned fry surges in small volumes.
- 3.Treating 40 L as "unlimited" for multiple generations of fry without a grow-out or export plan.
- 4.Hardy and forgiving in tap water. Males harass females endlessly if the sex ratio is wrong. Keep only males, or a one-male-to-two-female ratio at minimum.
About this species
Guppies are small livebearers that breed monthly in a stable tank. Males carry the colour. Females are larger, plainer, and pregnant for most of their adult life.
- Endler's Livebearer40L min · same group, comparable tank size
- Platy60L min · same group, similar adult size
- Molly80L min · same fish family
- Swordtail80L min · same fish family
- Sailfin Molly120L min · same fish family
- Amano Shrimpalso beginner peaceful, similar tank size
- Assassin Snailalso beginner peaceful, similar tank size
- Beckford Pencilfishalso beginner peaceful, similar tank size
- Black Neon Tetraalso beginner peaceful, similar tank size
- Black phantom tetraalso beginner peaceful, similar tank size
- Bloodfin tetraalso beginner peaceful, similar tank size
- Bronze corydoras tank mateslists this fish as a safe and recommended mate
- Cherry Barb tank mateslists this fish as a safe and recommended mate
- Corydoras Catfish tank mateslists this fish as a safe and recommended mate
- Dwarf Gourami tank mateslists this fish as a safe and recommended mate
- Harlequin Rasbora tank mateslists this fish as a safe and recommended mate
- Honey Gourami tank mateslists this fish as a safe and recommended mate
- Kuhli Loach tank matesnames this fish as a conditional pairing — read the pair page conditions
- Otocinclus tank matesnames this fish as a conditional pairing — read the pair page conditions
Plan grid
Key limits are above. Here: pH band, swim level, bioload, and activity.
Swim zones
Care snapshot
Quick compare before you buy. Not a score of how “good” the fish is.
- Beginner ease85
- Peacefulness90
- Community fit75
- Small-tank fit100
- Hardiness79
- Energy86
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Example setups
Starting points only. Run the pair checker for every fish you add.
Rough 90L+ layout: one calm centrepiece, 8–12 small tetras/rasboras, 6–8 corydoras-type bottom fish — verify every name in the pair checker before buying.
Safer directions include: Corydoras Catfish, Honey Gourami, Platy.
Compatibility
Tank mates for Guppy
Usually safer (engine GOOD): Corydoras Catfish, Honey Gourami, Platy. Conditional (CAUTION — read the pair page before buying): Betta, Tiger Barb. Avoid (RISKY): Jack Dempsey, Oscar. Every name links to a live pair check — the lists are a shortlist, not a stocking plan.
Usually safer
Open a pair page with this fish as the starting point.
Needs planning
Read the blocking rule on each pair page before experimenting.
Usually avoid
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Guppy + Corydoras Catfish
- Try Corydoras Catfish — open the pair check.
- Try Honey Gourami — open the pair check.
- Try Platy — open the pair check.
Behaviour and temperament
Guppies stay peaceful toward other species while males chase females without pause in a mixed tank. A male-heavy ratio shreds fins; one male to two or more females, or an all-male tank, is what keeps harassment from becoming the weekly chore. Fancy tails make every chase visible, so damage shows sooner than it does on short-finned livebearers. Fry appearing weekly in a settled tank is normal ownership, not a surprise event.
What sets them off
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper; stressed or crowded individuals can still test fins.
Predation: Not a predator toward similarly sized community fish; fry and dwarf shrimp are still fair game for most species.
Territory: Not strongly territorial, but still needs room so its working space does not overlap the next fish.
Planted tanks: excellent — easy plant ideas
In the glass: typical and warning signs
- Busy surface feeders; males flash colour constantly in a mixed sex group.
- Fry appear weekly in a settled tank — expect it.
- Clamped fins and shimmy in cold or dirty water.
- Males shredding one female's fins in a male-heavy tank.
- Males chase; fin damage is the tell that ratios or space are wrong.
- Female fins shredded → add females or pull males.
- Endlers and fancy guppies will hybridise; separate if you care about strains.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Water, food, and grouping
Hardness
medium-hard
Diet
omnivore
Guppies hammer surface flake, and that habit hides how often they need smaller, frequent meals rather than one heavy feed. Quality flake or micro-pellets two or three times a day in amounts finished in a minute beats a single feast that fouls the water. A little frozen or freeze-dried food a few times a week supports colour; constant rich protein plus leftovers is how tanks cloud. Make sure females get food, not only the showiest males.
Shrimp & snails
Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
Three or more, but the sex ratio is what matters. One male to two or three females, or all-male, prevents the females being chased to death.
Livebearers breed every few weeks. Plan sex ratios or a rehoming route before the first fry.
- Hold 22 to 28 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6.8 to 7.8 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Footprint: short wide tanks and tall narrow tanks fish differently for the same volume. Match the tank shape to the swim pattern, not just the litre count.
- Tank volume meets or exceeds 40L published minimum for adults.
- You can stock at least 3 individuals (group welfare).
- Heater can hold 22–28°C without cooking cooler-water tank mates.
- No known fin-nippers paired with long-finned fish unless you accept documented risk.
Explore and stocking hubs
Tank-mates hub, matching guides, category peers, and litre stocking lists around this species’ minimum tank.
Plan with tools
Check mates as pairs first, then add this fish in the tank builder for the full stocking.
Filtration & heating
A 40L minimum tank needs a filter rated for at least 160L/hr turnover and a heater to hold 22–28°C reliably.
Plant suggestions
Guppy does well in planted tanks. Plants compatible with 22–28°C and pH 6.8–7.8:
Research: verified · Confidence: high · 4 linked source(s). We do not invent citations.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- Seriously Fish. Poecilia reticulata
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Poecilia reticulata
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Poecilia reticulata
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
- Wikipedia. Guppy
Encyclopaedia overview; use specialist aquarium sources for your stock's real temperature/pH/footprint needs.
Evidence notes
- Care numbers are cross-checked across the linked sources and biased toward the conservative end; compatibility reflects typical hobby experience, not a lab prediction. Method and full source policy: /methodology.
Featured compatibility checks
Curated pair pages for Guppy. Each opens a full verdict — not just a list label.
Common questions about Guppy
- How big do Guppy get?
- Males stay around 3-4cm (mostly tail), females 5-6cm. The size matters less than the colony. Six guppies become twenty-six within a few months.
- What size tank does Guppy need?
- 60L is the practical floor. Smaller tanks crash under the bioload of a breeding colony, and males harass single females in cramped footprints.
- Are Guppy aggressive?
- Guppies stay peaceful toward other species while males chase females without pause in a mixed tank. A male-heavy ratio shreds fins; one male to two or more females, or an all-male tank, is what keeps harassment from becoming the weekly chore. Fancy tails make every chase visible, so damage shows sooner than it does on short-finned livebearers. Fry appearing weekly in a settled tank is normal ownership, not a surprise event.
- What is the most common mistake with Guppy?
- Ignoring sex ratios is the guppy mistake that turns a pretty starter tank into shredded females and a fry flood. One male with multiple females reduces harassment; several males with one female does the opposite. Plan the ratio and a backup plan for young before you buy the first bag. Colour morphs do not override basic livebearer maths.
- What fish can live with Guppy?
- The Guppy profile lists Corydoras Catfish, Honey Gourami, Platy among its safer pairings (engine-checked GOOD). Betta, Tiger Barb are conditional (CAUTION): workable only with the specific conditions on each pair page. Avoid Jack Dempsey, Oscar (RISKY). Run the pair checker for your exact water and tank size before stocking.