Rainbow Shark Care Guide
The Rainbow Shark (Epalzeorhynchos frenatum) is a popular freshwater fish among UK aquarists. Known for its dark body and vibrant red fins, it is an eye-catching species that adds colour and personality to larger community aquariums.
In this guide, you'll learn everything you need to know about Rainbow Shark care, including tank size, water conditions, compatibility, feeding, and typical UK prices - plus how to buy or sell them locally.
Quick facts about Rainbow Sharks
Rainbow sharks are river fish native to Southeast Asia. Despite their name and shark-like appearance, they are actually members of the carp family.
They are active bottom-dwellers that establish territories and spend much of their time exploring the aquarium.
Epalzeorhynchos frenatum
12-15 cm
Thailand and Southeast Asia
180L (48gal)
5-8 years
Semi-aggressive, territorial
22-28°C
Omnivore (algae, pellets, frozen foods, vegetable matter)
6.5-7.5
£4-£12 per fish
How Many Rainbow Sharks Should You Keep?
Rainbow sharks are best kept singly.
- One rainbow shark per aquarium is recommended
- Adults become increasingly territorial as they mature
- Large tanks with plenty of hiding places help reduce aggression
Keeping multiple rainbow sharks together often leads to:
- Territorial disputes
- Chasing behaviour
- Stress and injury
They are most successful as a single centrepiece bottom-dweller.
Ideal Tank Conditions for Rainbow Sharks
Providing the right environment helps rainbow sharks display natural behaviour and vibrant colours.
- Tank Setup: Spacious aquarium with open swimming areas and territories
- Substrate: Sand or smooth gravel
- Plants & Decor: Rocks, driftwood, caves, and sturdy plants
- Water Conditions: Clean, stable, well-oxygenated freshwater
- Filtration & Flow: Moderate to strong filtration
- Lighting: Moderate lighting
They enjoy having caves and shaded areas where they can establish territory.
Compatibility with Other Fish
Rainbow sharks can work well in larger community aquariums when carefully planned.
- Good Tankmates: bala sharks, giant danios, rainbowfish, silver dollars, Congo tetras, pearl gouramis, and larger peaceful barbs
- Avoid: red-tailed black sharks, harlequin sharks, other rainbow sharks, bottom-dwelling loaches of similar shape, and highly aggressive cichlids
They are most aggressive toward fish that occupy the same areas of the aquarium.
Are Rainbow Sharks Easy to Care For?
Rainbow sharks are moderately easy to care for and suitable for aquarists with some experience.
They require:
- Good water quality
- Plenty of swimming space
- Appropriate tankmates
- Territories and hiding places
They are hardy fish once established in a mature aquarium.
Rainbow Shark Price in the UK
In the UK, rainbow sharks typically cost between £4-£12 per fish.
Prices vary depending on:
- Size and age
- Availability
- Shop vs hobbyist sellers
Albino rainbow sharks often command slightly higher prices.
Where to Buy Rainbow Sharks in the UK
Rainbow sharks are widely available in UK aquarium shops and from hobbyist fishkeepers.
Sourcing fish locally can:
- Reduce transport stress
- Allow you to inspect health and body condition
- Offer better value
TankMate UK helps connect fishkeepers who want to buy, sell, or rehome fish safely - without shipping.
Can You Sell Rainbow Sharks?
Yes - rainbow sharks are commonly sold and rehomed by hobbyists.
Selling locally is often the best option, as it:
- Minimises stress for the fish
- Avoids the risks of shipping
- Helps connect suitable keepers
TankMate UK allows you to list fish quickly and find local buyers.
Feeding Rainbow Sharks
Rainbow sharks are omnivorous and opportunistic feeders.
Key Tips
- Feed quality sinking pellets and wafers
- Supplement with algae wafers and vegetable matter
- Offer frozen foods such as bloodworms and brine shrimp
- Feed small portions 1-2 times daily
A varied diet helps maintain vibrant colours and strong health.
Common Problems with Rainbow Sharks
Territorial aggression, often caused by:
- Small tank sizes
- Similar-shaped tankmates
- Lack of hiding places
Stress and hiding, linked to:
- Poor water quality
- Inadequate territory
Colour fading, caused by:
- Stress
- Poor diet
- Inappropriate water conditions
Why Rainbow Sharks Are So Popular
- Striking black body and red fins
- Active and entertaining behaviour
- Hardy and adaptable
- Excellent centrepiece fish for larger community tanks
- Widely available and affordable
When kept correctly, rainbow sharks become colourful and charismatic aquarium residents that bring plenty of activity and personality to a tank.
Frequently Asked Questions
They are semi-aggressive and territorial, particularly towards similar-shaped fish.
Yes, they often coexist well because they occupy different areas of the aquarium.
Yes, they will graze algae, particularly when young, but should not be relied upon solely for algae control.
At least 180 litres, with plenty of swimming space and hiding places.
Looking to Buy or Sell Rainbow Sharks Locally?
TankMate UK connects fishkeepers who want to buy, sell, or rehome fish safely within their local area.
Whether you're searching for a colourful centrepiece fish or looking to rehome one responsibly, you can:
- Browse fish available near you
- List your own fish in minutes
- Avoid the risks of shipping
Explore local listings with TankMate UK and find the right fish for your aquarium.