Every week we get emails that start the same way: "I'm new to this and I don't know what fish to buy first." This page is the answer we'd send — I'm Tom, the nano-tank and beginner writer on the site, and the ten species below come straight from three years of "what do I do now?" questions on my YouTube channel.
The ten species below are the ones we'd happily put in a cycled 90 L tank and send home with a first-time keeper, confident they'll still be thriving six months later. They're picked against four criteria: hardy in UK conditions, peaceful in a community tank, widely in stock year-round, and tolerant of the minor parameter swings that every new aquarist's tank will have.
This is roughly the stocking we'd put in a 90 L first tank — a mixed school of rasboras, half a dozen livebearers, a small corydoras pod. Photo: Tropical Fish Co.
UK tap water is typically medium-to-hard (10-25 dGH) with pH 7.2-7.8 [5]. That's ideal for livebearers and most South American tetras but uncomfortable for soft-water specialists (Chocolate Gouramis, wild Discus, some Apistogramma). Every species below thrives in standard UK tap water without remineralisation.
Five facts most "best beginner fish" lists never mention
- Livebearers have been in the UK hobby since 1908. The Guppy was the first tropical ornamental imported to the UK in commercial volume; every beginner list since has put it in the top 3 [4].
- "Cycling the tank" means growing bacteria, not fish. A new tank needs 4–6 weeks of ammonia-dosing (fish-less) or small-stocking-plus- testing to build the nitrogen-processing bacteria that keep the fish alive [6].
- Neon Tetras are MORE fragile than Cardinals in new tanks. Despite being the "classic beginner fish", neons suffer badly in the parameter swings of a tank under 8 weeks old [1]. Harlequin Rasboras are our hardier swap.
- Every fish on this list is commercially farmed. None are wild-caught, so there's no conservation trade-off in buying them. Compare that to some cichlids and catfish where wild-catching still dominates [3].
- The single biggest beginner killer is overfeeding, not wrong fish. More beginner tanks crash from ammonia spikes caused by uneaten food than from anything on the water-chemistry sheet. Feed what they eat in 30 seconds, twice a day. That's it.
Watch: what a stable beginner community tank looks like
Before spending any money — watch what you're aiming at. The clip below is our in-house 90 L first-stocking showcase.
1. Guppy (Poecilia reticulata)
The livebearer that made tropical fishkeeping a hobby rather than a rich person's pastime. Guppies tolerate the entire range of UK tap water, eat anything, and come in dozens of colour strains from £2.50 specimens to £30 show-quality fancies.
Quick stats: Size 3-6cm | Temp 22-28°C | pH 7.0-8.5 | Hardness 10-25 dGH | Tank mates: everything peaceful | Price: £2.50-£8 each
Why it's great for beginners:
- Tolerates UK hard tap water perfectly — no water preparation needed
- Eats any dry or frozen food; forgives missed feeds
- Kept as males-only for no-fry tanks, or 1:3 male-to-female for breeding
- Never outgrows a 60L tank
- Short life cycle (2-3 years) means you see the full lifespan before committing to a second species
Group size: 5-6 minimum for mixed-sex; males can be kept in smaller groups or solo
Full care guide: Guppy care.
2. Neon Tetra (Paracheirodon innesi)
The small schooling tetra that every beginner has heard of, and still one of the most rewarding in a mature planted tank. A dense school of twenty Neons moving as one through aquascaped foreground plants is one of the classic sights of the hobby.
Quick stats: Size 3cm | Temp 22-26°C | pH 6.0-7.5 | Hardness 2-10 dGH | Tank mates: small peaceful community | Price: £1.80-£2.50 each
Why it's great for beginners:
- Tight shoaling behaviour — they actually school together, unlike some nominally-schooling species
- Short (3cm) so 10-15 of them fit a 60L tank comfortably
- Widely available year-round, always in stock, always at reasonable prices
- One of the few tetras that breeds in captivity at commercial scale, so stock is farmed rather than wild-caught
Neons are the single most common casualty of beginners stocking a newly-cycled tank. They're sensitive to the small parameter swings that happen in the first 6-8 weeks after cycling completes. Add Neons last, ideally 6+ weeks after the first fish went in.
Group size: 10 minimum; 15-20 looks much better and they school tighter
Full care guide: Neon Tetra care.
3. Platy (Xiphophorus maculatus)
The hardiest livebearer in the hobby. Platies come in red, blue, orange, variegated, and sunset colour strains, stay compact at 5-6cm, and breed with zero encouragement. If Guppies are the entry-level livebearer, Platies are the upgrade for anyone who wants slightly chunkier fish with more visual impact.
Quick stats: Size 5-6cm | Temp 22-26°C | pH 7.0-8.3 | Hardness 10-25 dGH | Tank mates: every peaceful community species | Price: £3-£5 each
Why it's great for beginners:
- Built for UK hard tap water — one of the few fish that actively prefers higher pH
- Livebearer, so you see fry in the tank within a few weeks
- Peaceful with every other species on this list
- Hardy enough to survive almost any beginner mistake short of skipping the cycle
- Lives 2-3 years
Group size: 3-5 (livebearers don't need strict shoals); mixed-sex works but expect fry
Full care guide: Platy care.
4. Cherry Shrimp (Neocaridina davidi)
The best value in the hobby. A starter colony of 10 Cherry Shrimp is around £30 and, given a planted tank and no predators, turns into 100+ shrimp within a year. They eat algae, biofilm, and leftover food. They're peaceful with every community fish species that won't fit them in its mouth.
Quick stats: Size 2-3cm | Temp 18-26°C | pH 6.5-8.0 | Hardness 6-20 dGH | Tank mates: small peaceful fish, other shrimp | Price: £2-£4 each (groups of 10-20)
Why it's great for beginners:
- Tolerant of cooler room temperatures (18°C+), so survives heater failure
- Breeds without any intervention
- Actively cleans the tank — visible results within weeks
- Teaches water chemistry because shrimp are sensitive to parameter swings before fish are
- 10 shrimp cost less than a single fancy guppy
Cherry Shrimp come in red, blue, yellow, chocolate, snowball white, and other colours — but they're all the same species (Neocaridina davidi) and crossbreed readily. If you want to maintain colour purity in a breeding colony, stock ONE colour per tank. Mixed colonies muddy to brown/grey within a generation.
Group size: 10 minimum to establish a colony; 20+ gives faster colonisation
Full care guide: Cherry Shrimp care.
5. Molly (Poecilia sphenops / Poecilia latipinna)
The bigger cousin of the Guppy and Platy. Mollies hit 8-12cm depending on strain, producing real visual presence in a 90L+ tank, and they come in black, dalmatian, gold, silver, sailfin, and balloon varieties. They tolerate a wider salinity range than any other common tropical fish — some keepers run low-salt brackish Molly tanks.
Quick stats: Size 8-12cm | Temp 24-28°C | pH 7.5-8.5 | Hardness 15-30 dGH | Tank mates: peaceful community | Price: £4-£8 each
Why it's great for beginners:
- Bigger fish means more visible personality and interaction
- Extremely hardy — tolerate mild water chemistry issues that would stress smaller fish
- Livebearer, so fry show up naturally
- Loves hard UK tap water
- Active surface-to-mid swimmers, fill the upper water column
Mollies get too big for a 60L. Minimum 90L for Short-fin varieties, 120L for Sailfin. Undersize them and they get aggressive with tank mates.
Group size: 3-5, ideally more females than males
Full care guide: Molly care.
6. Harlequin Rasbora (Trigonostigma heteromorpha)
Our single most-recommended schooling fish for first-time aquarists. The Harlequin is hardier than any tetra, tolerates the entire UK pH range, schools tightly, and moves beautifully across the middle of the water column. If you want one peaceful schooling species, this is what we'd pick.
Quick stats: Size 4cm | Temp 22-28°C | pH 6.0-8.0 | Hardness 2-15 dGH | Tank mates: small peaceful community | Price: £2.50-£4 each
Why it's great for beginners:
- Widest pH tolerance of any common schooler (6.0-8.0) — copes with any UK tap water
- Tight shoaling behaviour
- Adult size fits 60L+ tanks easily
- Striking copper-orange body with black triangular patch — more visual impact per pound than Neons
- Less fussy about tank maturity than Neons
Group size: 8 minimum; 10-12 is ideal
Full care guide: Harlequin Rasbora care.
7. Corydoras Catfish (Corydoras spp.)
The community tank's essential bottom-dweller. Bronze and Peppered Corydoras are the hardiest and most widely stocked; Panda, Sterbai, and Julii Corys are the slightly fancier (and more expensive) strains. Whichever you pick, they patrol the substrate, eat leftover food, and behave like a small friendly gang.
Quick stats: Size 5-7cm | Temp 22-26°C | pH 6.5-7.8 | Hardness 5-15 dGH | Tank mates: every peaceful community species | Price: £4-£8 each
Why it's great for beginners:
- Cleans up uneaten food before it fouls the substrate
- Peaceful with every fish species on this list
- Hardy, long-lived (5-10 years), and active during the day
- Fun to watch — they occasionally dash to the surface for a gulp of air (they're facultative air-breathers)
Corydoras sift substrate with their barbels (the whisker-like sensors under their mouth). Sharp gravel wears barbels down and causes infections. Use smooth rounded gravel or fine sand.
Group size: 6 minimum — they're genuinely schooling catfish and stress when kept in smaller numbers
Full care guide: Corydoras care.
8. Zebra Danio & Celestial Pearl Danio (Danio rerio / Celestichthys margaritatus)
Zebra Danios are the classic first schooling fish for UK beginners — they tolerate cooler water (18-24°C) than any other species on this list, which makes them the best pick for a room without reliable heating. Celestial Pearl Danios are the modern upgrade: smaller, more colourful, and stunning in nano planted tanks.
Quick stats (Zebra): Size 5cm | Temp 18-24°C | pH 6.5-7.5 | Tank mates: active community | Price: £2.50-£4 each
Quick stats (Celestial Pearl): Size 2cm | Temp 20-25°C | pH 6.5-7.5 | Tank mates: small peaceful community | Price: £4-£7 each
Why they're great for beginners:
- Danios as a genus tolerate cooler temperatures than any other tropical
- Active, constant swimming — fills the upper water column
- Small enough for 60L tanks
- Celestial Pearls add a splash of red-orange finnage that most hardy species lack
Group size: 6-8 minimum for both
Full care guide: Celestial Pearl Danio care.
9. Bristlenose Pleco (Ancistrus sp.)
The algae eater worth buying. Unlike the misnamed "Common Pleco" that grows to 45cm, the Bristlenose stays at 10-12cm, actively eats algae throughout its life, and fits a 90L+ community tank perfectly. One Bristlenose handles a medium-sized tank's algae without touching your plants.
Quick stats: Size 10-12cm | Temp 22-28°C | pH 6.5-8.0 | Hardness 4-20 dGH | Tank mates: every peaceful community species | Price: £12-£25 each
Why it's great for beginners:
- Genuine algae eater (not the cosmetic algae-eater-but-really-just-sucks-on-glass variety)
- Max 12cm — doesn't outgrow sensible tanks
- Long-lived (10-15 years)
- Colour strains include albino, snow white, and long-finned
- Peaceful with every community species
Bristlenose Plecos rasp driftwood for fibre. Without driftwood in the tank, they can develop digestive issues. A single piece of Mopani or Malaysian driftwood is enough.
Group size: Solitary (one per tank) or a breeding pair
Full care guide: Bristlenose Pleco care.
What your 90 L tank can look like six months in. Diffused lighting, mid-ground java fern + anubias, gentle flow, a settled community. Photo: Tropical Fish Co.
10. Honey Gourami (Trichogaster chuna)
The gentlest, prettiest gourami for beginners. A pair of Honey Gouramis adds a golden centrepiece to a planted community tank without the aggression that Three-Spot or Pearl Gouramis show. They breathe atmospheric air (labyrinth organ), so they'll survive low-oxygen incidents that would kill other species.
Quick stats: Size 5-7cm | Temp 24-28°C | pH 6.0-7.5 | Hardness 4-15 dGH | Tank mates: peaceful community | Price: £6-£10 each
Why it's great for beginners:
- Genuinely peaceful — one of the few gouramis suitable for mixed community tanks
- Labyrinth organ makes them tolerant of low-oxygen water
- Striking gold/orange colour with pale blue highlights
- Interactive — they recognise their keeper and follow you at the front glass
- Smaller than other gouramis, so fit 90L+ tanks
Group size: Pair (male and female) or solo. Two males in the same tank will fight.
Full care guide: Honey Gourami care.
Fish to avoid as a beginner
Despite how often they're marketed to beginners, these species cause the most first-tank disasters:
Angelfish juveniles. Sensitive to water quality, territorial as they mature, and they eventually eat small tetras. Reserve for a second, larger tank once you have cycling and water changes dialled in.
Common Plecos. Grow to 40-45cm, produce huge waste loads, and only the Bristlenose variety stays small. Any shop selling a 5cm Pleco to a beginner for a 60L tank is setting them up for failure.
Discus. The king of the hobby, but demand pristine soft warm water, daily attention, and experience reading fish behaviour. Not a first fish.
Cichlids (most). Territorial, aggressive to tank mates, and specific water requirements. Rams and Apistogramma look approachable but are genuinely intermediate-level fish.
Chinese Algae Eater. Peaceful when small, becomes aggressive and territorial with age, eventually attaching to other fish to rasp their slime coat. Stick with Bristlenose Plecos or Otocinclus instead.
Wild-caught species. Shipping stress and parasite load are higher. Look for "tank-bred" or "aquaculture" on the label.
Goldfish. Not tropical — they want cooler water (18-22°C) and produce 3-4x the waste of similar-sized tropical fish. Need 100L+ per fish. A beginner tropical setup is not a goldfish home.
The Zebra Danio used to be my number one beginner recommendation. Hardy, peaceful in groups, tolerates cooler water. But I've seen too many beginners stock 6 Zebra Danios in a 60L and end up with aggression issues — they're nippier and more active than most small community fish, and they can stress shyer tank mates. Harlequin Rasboras fill the same niche with better temperament.
Stocking your first tank
Don't buy fish at random — plan the whole tank up front. Three proven stocking plans:
60L community (starter)
- Schooling centrepiece: 6-8 Harlequin Rasboras
- Livebearers: 4 Platies (mixed colours, 1 male 3 females)
- Bottom-dwellers: 5 Bronze Corydoras
- Clean-up: 10 Cherry Shrimp
Total fish load: moderate. Add over 6 weeks in the order above.
90L community (classic)
- Schooling centrepiece: 10 Cardinal Tetras OR 12 Harlequin Rasboras
- Livebearers: 6 Guppies (males only, mixed strains)
- Bottom-dwellers: 6 Bronze Corydoras
- Algae crew: 1 Bristlenose Pleco
- Invertebrates: 10 Amano or Cherry Shrimp
Total fish load: full but not overstocked. Add over 8 weeks.
120L showpiece
- Centrepiece: A pair of Angelfish OR 2 Honey Gouramis
- Schooling fish: 15 Cardinal Tetras OR 12 Ember Tetras
- Livebearers: 5 Platies
- Bottom-dwellers: 8 Peppered Corydoras
- Algae crew: 1 Bristlenose Pleco
- Invertebrates: 15 Amano Shrimp
Total fish load: high — requires weekly 30% water changes and a proper external filter.
Before you buy: check your setup
Every species on this page assumes a cycled tank — one that's been running for 4-6 weeks with ammonia-only dosing until ammonia and nitrite both read 0 within 24 hours of feeding. If your tank isn't cycled, the fish will die within days, regardless of how hardy they are.
Full cycling walk-through: Beginner Aquarium Setup.
Fish-in cycling (adding fish to an uncycled tank and letting the nitrogen cycle establish around them) works but causes measurable harm to the fish — burnt gills, shortened lifespan, and high casualty rates. Every fish in this guide deserves a cycled tank. Spend 4-6 weeks on fishless cycling before your first order.
Further reading
- Beginner Aquarium Setup Guide
- Tropical Fish for Sale UK — Top 10 Picks
- How to Buy Tropical Fish Online in the UK
- Guppy care guide
- Neon Tetra care guide
- Platy care guide
- Cherry Shrimp care guide
- Molly care guide
- Harlequin Rasbora care guide
- Corydoras care guide
- Celestial Pearl Danio care guide
- Bristlenose Pleco care guide
- Honey Gourami care guide
- Water chemistry basics
- Live plants for beginners
Ready to stock your first tank?
Browse the full beginner-friendly range: fresh water fish and shrimp and invertebrates.
If you'd like us to check your stocking plan before ordering — tank size, species mix, water parameters — email us with the details. We'd rather spend 10 minutes on email now than ship fish into a tank that won't suit them.