Cycle the tank first
A new aquarium needs four to six weeks of fishless cycling before you add stock, so the filter can grow the bacteria that convert ammonia to nitrate. Adding fish to an uncycled tank is the most common cause of early losses.
Quick answer
How much do fish cost in the UK?
Fish in the UK typically cost £2–£200. PetTrader lists them from licensed breeders, private sellers and rescues, with 6 species guides, prices, locations and health details on every advert.
- Typical price
- £2–£200
- Species guides
- 6
- Live adverts
- 0
- Seller checks
- ID verified
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Check compatibility
Research adult size, temperament and water parameters before mixing species. Many fish sold small reach 30cm or more and will outgrow a starter tank within a year.
Transporting fish safely
Bag fish with plenty of air, keep them dark and insulated, and float the sealed bag in the destination tank to equalise temperature before drip-acclimatising over 30–60 minutes.
How much do fish cost in the UK?
Fish typically sell for £2–£200 in the UK. Price depends on the breed or variety, health testing and registration paperwork, the seller's location and the time of year. An advert priced well below the band for its breed is one of the most common signs of an unlicensed seller or a scam.
| Breed | Typical UK price |
|---|---|
| Koi Carp fry | £20–£500 |
| Goldfish fry | £3–£40 |
| Betta Fish fry | £8–£60 |
| Guppy fry | £2–£15 |
| Discus Fish juveniles | £30–£150 |
| Cichlids juveniles | £5–£60 |
Fish for sale: common questions
How much do fish cost in the UK?+
Most aquarium fish cost £2–£200. Community tropicals such as tetras, guppies and corydoras are a few pounds each, bettas and cichlids £10–£40, and marine fish and quality koi run into the hundreds. The tank, filter and heater are the main outlay.
Do I need to cycle a tank before adding fish?+
Yes. A new tank needs four to six weeks of fishless cycling so the filter grows the bacteria that convert ammonia to nitrite and then nitrate. Adding fish to an uncycled tank is the single most common reason beginners lose them.
How many fish can I keep in my tank?+
Stocking depends on adult size, waste output and swimming style rather than a simple inch-per-litre rule. Research the adult size of every species before you buy — common plecos, silver sharks and goldfish all outgrow the tanks they are usually sold for.
Which fish are best for beginners?+
For a tropical community, guppies, platies, danios, corydoras and neon or ember tetras are hardy and inexpensive. For coldwater, white cloud mountain minnows suit smaller tanks; goldfish need far more space than most people expect.
How do I transport fish home safely?+
Keep the bag dark and insulated, get home quickly, then float the sealed bag in the tank for 15–20 minutes to match temperature before drip-acclimatising to the water chemistry. Net the fish into the tank rather than pouring in transport water.
How much do koi and pond fish cost?+
Small pond goldfish and shubunkins are a few pounds each, standard koi £20–£100, and Japanese-bred show-quality koi many hundreds. Any pond fish needs proper filtration, depth for winter and protection from herons.
How do I avoid scams when buying fish online?+
View the animal in person at the seller's own home before any money changes hands, keep all messages inside PetTrader so there is a record, and never pay by bank transfer, gift card or crypto to someone you have not met. Every PetTrader seller completes a photo-ID and live selfie check, and verified accounts carry a badge, and you can report an advert from the listing page.
Where to advertise fish for sale
Selling rather than buying? Identity-verified private sellers get their first advert free, and the first 200 businesses and breeders get 12 months free. See all fish for sale, read where to advertise fish in the UK for the costs and legal rules, or rehome a pet you already own.