Your guppy is pregnant (they usually are) and the clock is ticking: 21–30 days from mating to 20–50 live fry. What you prepare in the next week decides whether you raise a healthy batch or find two survivors hiding in the filter. Here's the complete checklist, in priority order.
1. Choose your nursery strategy
- Dense plant cover in the main tank (our pick): zero stress on mum, natural selection does the rest. Works best with a heavily planted corner.
- Separate birthing tank: a small cycled tank with a sponge filter. Move her a few days before delivery — never during labour — and return her straight after (she WILL eat fry).
- Breeder box: last resort; confinement stresses females and can delay birth. Max 1–2 days.
2. Plant the fry cover (do this first)
Fry survive by hiding for their first 2 weeks. The two best options are named for the job:
- Guppy grass — fast-growing floating thickets; the classic fry jungle
- Java or christmas moss — dense bottom cover that also grows biofilm fry graze on
Plant them a week or two early so they settle before the birth.
3. Stock the fry pantry
Fry are free-swimming and hungry from hour one. Have ready: finely crushed quality flake (a bag and a rolling pin works), and for faster growth, powdered fry food. Feed tiny amounts 2–3× daily and remove leftovers — fry tanks foul fast (see water quality guide).
4. Set the water
- Temperature 25–27°C — warm water = faster gestation and stronger fry (temperature guide)
- Ammonia/nitrite zero, stable pH — fry tolerate far less than adults
- Gentle flow only: sponge filter or pre-filter sponge over the intake so fry don't get eaten by the equipment
5. Know the delivery signals
Squared-off belly, jet-black gravid spot, hiding, refusing food, hovering near the heater — when these stack up, birth is 24–48 hours away. Full list: 9 signs of guppy delivery. Not 100% sure she's pregnant? Check the 6 signs.
After the birth: the first 48 hours
- Return/leave mum with the colony — separate her from fry immediately
- Don't panic-count — fry hide for days; you'll see the real number at week two
- Start feeding within hours — tiny, frequent meals beat big ones
- Plan for growth: 20–50 juveniles need space or a rehoming plan by month two — or breed on purpose with these 12 tips
FAQ
Do I need a heater in Australia?
For fry, yes in most states outside summer — stable 25°C+ makes a visible difference to survival and growth rates.
How fast will fry show colour?
Males start colouring at 4–6 weeks — that's when you'll know if the batch inherited dad's looks. Genetics decide everything.
Start with genetics worth breeding
Beautiful fry come from beautiful parents: our Sydney-bred fancy guppies — Albino Full Red, 24K Gold, Blue Neon and more — ship Australia-wide with a Live Arrival Guarantee.
