Species · Livebearers
Platy
Xiphophorus maculatus
One of the most cheerful, forgiving beginner fish there is — a hardy hard-water livebearer that comes in every colour. Just know a mixed group will breed, and buy healthy stock.
Difficulty: BeginnerTropical community tank✓ Fact-checked care guide
Quick facts
| Adult size | ~5 cm / 2 in |
|---|---|
| Minimum tank | ~40 L / 10 US gal for a small group — SeriouslyFish recommends a 60 × 30 cm base |
| Temperature | 22–25 °C / 72–77 °F (within the species range of 20–26 °C / 68–79 °F) |
| pH | 7.0–8.2 (neutral to alkaline) |
| Hardness | 10–30 dGH — a hard-water fish |
| Filtration & flow | Cycled, gentle-to-moderate filtration |
| Diet | Omnivore — a quality flake/pellet base plus small live/frozen foods and some vegetable matter |
| Social | Active and sociable — keep a small group; with mixed sexes keep 2–3 females per male |
| Temperament | Very peaceful |
| Lifespan | 2–3 years |
Overview
The platy (Xiphophorus maculatus) is a small, endlessly colourful livebearer and one of the easiest fish to start with — hardy, active, and good-natured, in a rainbow of bred varieties (mickey mouse, wagtail, sunset and more).
Two honest notes: like guppies it is a livebearer, so a mixed group will breed steadily, and years of mass-breeding mean some stock is less hardy than it should be — buy healthy, active fish from a good source.
Water & tank
Platies are a hard-water fish: they do best at pH 7.0–8.2 in moderately hard to hard water (10–30 dGH). They keep their colour and health best in neutral-to-alkaline water, which is what much tap water already is.
Give a small group at least ~40 L / 10 US gal (SeriouslyFish recommends a 60 × 30 cm base), planted, with gentle filtration and a cycled tank before they go in.
Feeding
Omnivores that eat almost anything — use a good flake or pellet as the base and add small live/frozen foods and the occasional blanched vegetable for variety.
Feed small amounts once or twice a day, only what they finish quickly.
Behaviour & tankmates
A model peaceful community fish — great with other livebearers, small tetras and rasboras, corydoras and other calm species. Avoid fin-nippers and anything large enough to eat them.
Keep 2–3 females per male so females aren't pestered; a single-sex group avoids fry entirely.
What to expect
Expect colour, activity, and fry — a mixed group produces live young regularly, and in a planted community tank the population tends to self-limit as other fish eat the surplus.
Myths, kindly busted
“Platies are so hardy they thrive in any water.”
They are hardy, but they are a hard-water fish — long-term they want neutral-to-alkaline, moderately hard or harder water, not soft acidic tanks.
“A few platies will stay a few platies.”
They are prolific livebearers — a mixed group breeds continuously. Plan for fry or keep one sex.
When to act
We triage, not diagnose — but these are worth a closer look (starting with a water test):
- Clamped fins, lethargy or loss of colour — test the water first (ammonia, nitrite, nitrate).
- White spots, fungus or fin rot — common in stressed or inbred stock; act early and check water quality.
Sources & further reading
- SeriouslyFish — Xiphophorus maculatus — Adult ~50 mm SL; recommended 60 × 30 cm base; temperature 20–26 °C / 68–79 °F; pH 7.0–8.2; hardness 10–30 dGH (hard water); peaceful, beginner; livebearer; commercial stock often less hardy — buy quality.
Written & fact-checked by The Finfern Team against the sources above — kind, general guidance, not a diagnosis. If something looks wrong, test your water and, if it persists, contact a fish-savvy vet.
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