Guppy vs Platy vs Molly Comparison Guide: Livebearer Pick
Three livebearers dominate every Singapore beginner shelf, and they all look deceptively similar in the bag. The guppy vs platy vs molly question comes down to tank size, water hardness and how many fry you can rehome before the tank crashes. This guide from Gensou Aquascaping at 5 Everton Park breaks down each species against PUB tap conditions and gives you a clear pick by use-case.
Quick Verdict
Pick guppies if you want maximum colour in a 40-litre nano and do not mind 90+ fry every month. Pick platies if you want the hardiest beginner livebearer with manageable broods and peaceful temperament. Pick mollies only if you have 100 litres or more, harder water, and want a larger active midwater fish that tolerates brackish setups.
Guppy: The Colour King
Guppies (Poecilia reticulata) cap at 3-5cm and are the smallest of the trio. Males flaunt elaborate finnage in every colour imaginable; females stay drab and pregnant for most of their adult life. Water tolerance is broad — pH 6.8-8.0, GH 5-15, temperature 24-28°C — but they breed obsessively. Expect a single female to drop 30-90 fry every 30 days, and they will out-compete and out-breed everything in a community tank within months.
Platy: The Hardy All-Rounder
Platies (Xiphophorus maculatus) hit 5-6cm with stockier bodies and shorter fins. Mickey mouse, sunset, wagtail and tuxedo morphs are common in Singapore shops. They are arguably the toughest of the three, shrugging off pH swings between 6.8-8.2 and tolerating GH 8-20. Broods run 20-40 fry monthly — half the burden of guppies. Temperament is genuinely peaceful, with no chasing or fin-nipping, which makes them ideal for community aquascapes alongside freshwater shrimp.
Molly: The Brackish-Tolerant Heavyweight
Mollies (Poecilia sphenops and P. latipinna) reach 8-12cm and need real swimming room — 80 litres minimum for a trio, 150 litres for sailfins. They prefer harder, more alkaline water (pH 7.5-8.5, GH 12-25) and many keepers add a teaspoon of marine salt per 10 litres to mimic brackish estuaries. Mollies graze algae actively but produce a heavy bioload, so over-filtration with a quality aquarium filter is non-negotiable. Broods run 20-40 fry monthly.
Side-by-Side Spec Comparison
On size, guppies sit at 4cm, platies at 5cm, mollies at 10cm — a 2.5x range that drives every other decision. On minimum tank, guppies need 40 litres, platies 60 litres, mollies 100 litres. On hardness, guppies and platies handle Singapore PUB tap (GH 2-4) with a pinch of crushed coral; mollies need significant remineralisation. On fry output, guppies dump 60-90 monthly, mollies and platies 20-40. On price, all three sit in the SGD 2-8 bracket for shop-grade fish, with show guppies climbing to SGD 30-80 and balloon mollies hitting SGD 15.
Decision Framework
If your tank is under 60 litres, the choice is guppy or platy — mollies will be miserable. If you cannot rehome fry constantly and dislike crashing populations, skip guppies and pick platies. If you specifically want a fish that grazes hair algae and you have 100+ litres with harder water, mollies earn their spot. If you want all three together, only platies and mollies cohabit reliably; guppy males get harassed by molly males in mixed tanks.
Singapore Sourcing and Pricing
Polyart, Iwarna and C328 Clementi stock all three livebearers year-round. Shop-grade guppies run SGD 2-4 each, platies SGD 3-6, common mollies SGD 4-8 and sailfin mollies SGD 8-15. For show-grade guppies (Moscow blue, full red albino, koi), Carousell breeders in Yishun and Tampines list pairs at SGD 25-80. Petopia carries balloon and lyretail molly variants. Pair any of them with quality food from the tropical fish food range and a stable mature filter.
Common Mistakes
The biggest error is buying mixed-sex pairs without a fry plan. A trio of female guppies pregnant on arrival can produce 200 fry in three months. Second mistake: keeping mollies in pure soft Singapore tap without remineralisation, which leads to shimmies and bacterial infections. Third: putting all three species in a single 60-litre tank — mollies will outcompete the smaller two for food and the tank will crash from bioload within weeks.
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5 Everton Park #01-34B, Singapore 080005 · Open daily 11am – 8pm
