Why choose marine fish?

Marine aquariums are more complex than freshwater setups, but the results make it absolutely worthwhile. A beginner friendly setup should include:

  • Good filtration - ideally using a protein skimmer
  • Stable temperature - between 25-26°C
  • Consistent salinity - 1.023-1.025 specific gravity
  • Regular water testing - for ammonia, nitrite, nitrate, and pH
  • A regular maintenance routine 
  • Peaceful and hardy fish

If you've not got your setup ready yet, check out our Complete Guide To Keeping Marine Fish.

Tip: Try starting with just fish and live rock before adding corals as it is easier to maintain and ideal for beginners.

Preparing your tank for stocking

Before adding any fish, allow your time for cycling. This process allows beneficial bacteria to establish in your filter, preventing ammonia and nitrite spikes so that the water is safe for fish.

Run your system and equipment for a few weeks with live rock and filter media. Add an ammonia source kickstarts the cycle. Make sure to wait for the water tests to show ammonia and nitrite at zero before adding your first fish.

Stock up on our test kits today to keep your water safe.

Marine aquarium with tangs and clownfish, coral and rockwork
Stocking across the different levels of the tank creates movement and colour throughout the whole aquarium

Recommended marine fish for beginners

Below is a brief guide to some of the most popular fish for new aquariums, selected by their beauty, temperament, and ease of care.

ZoneSpeciesMinimum VolumeTemperamentExperience LevelNotes
TopOcellaris Clownfish - Amphiprion ocellaris75LPeacefulBeginnerHardy and easy to feed, great to pair with anemones
Yellowtail Damselfish - Chrysiptera parasema75LSemi-aggressiveBeginnerHardy but territorial in small setups
MiddleChromis (Green or Blue) - Chromis viridis100LPeacefulBeginnerSchooling, reef-safe fish that add constant movement
Royal Gramma - Gramma loreto80LPeacefulYesVibrant colouration, hides amongst rocks
Banggai Cardinal - Pterapogon kauderni100LPeacefulYesSlow moving and great for smaller setups
BottomYellow Watchman Goby - Cryptocentrus cinctus100LPeacefulYesSifts sad and pairs well with some shrimp
Blenny - Ecsenius spp.100LPeacefulYesHelps to control algae
Cleaner Shrimp - Lysmata amboinensis75LPeacefulYesA reef safe addition for better hygiene

Blenny fish in a marine aquarium
Blennies thrive at the bottom of your tank where they can forage for algae

Beginner marine fish and why we recommend them

Clownfish

Known for being hardy, social, and full of personality, Ocellaris and True Percula are perfect for beginners as they easily adapt to pellets, flakes, or frozen foods. Although they don't require anemones to be present to thrive, they may naturally bond with one if present.

Ocellaris Clownfish in a marine aquarium with anemones, coral, and rockwork
Ocallaris Clownfish are most popular for beginners, adding a vibrant splash of colour to the tank

Yellowtail and Talbot's Damselfish

Damselfish are a very hardy fish as they tolerate a wide range of water conditions. Talbot's Damsels are very peaceful and brightly coloured, making them great additions. To avoid territorial behaviour, introduce them last.

Green Chromis

These peaceful, active fish school by nature. They bring gentle but constant movement to the higher levels of your water. They are recommended to keep in groups to support their natural instinctive behaviour.

Royal Gramma

These reef-safe fish are shy and enjoy hiding spots but grow more confident as they settle. They are perfect for peaceful communities.

Banggai Cardinalfish

These distinctive Cardinalfish prefer a gentle flow and a calm environment. They make beautiful display fish with their elegant colouration.

Banggai Cardinalfish in a marine aquarium
Banggai Cardinalfish are great in beginner aquariums, but prefer gentle water movement

Yellow Tang

Yellow Tangs are hardy algae grazers that are ideal for large aquariums. They are to be kept in tanks 200L+ in size, adding beautiful colours and keeping your surfaces clean.

Eightline Wrasse

These eye-catching Wrasse are more suited to intermediate keepers but are a rewarding once your system matures. Keep the sand bed clean for burrowing.

At Swell UK, we stock a large range of marine species perfect for beginner and experienced fishkeepers alike.

Feeding your fish

Variety is essential in keeping your fish healthy and colourful. Feed with:

  • High quality marine flakes and pellets
  • Frozen brine shrimp, mysis shrimp, and krill
  • Seaweed or algae sheets for herbivores like tangs and blennies

Keep your reef thriving with our selection of premium marine food.

Marine tank care tips

Stable conditions are the key for succeding:

  • Test water weekly with a test kit
  • Perform 10-15% water changes every 2 weeks
  • Top up with RO water to maintain salinity
  • Clean glass, skimmer, and pumps regularly
  • Quarantine new fish before adding

Explore our range of marine water quality products to make upkeep simple.

Cleaner shrimp in a marine aquarium cleaning rockwork.
Cleaner shrimp are an ideal clean-up species, consuming algae in your tank

Ready to stock your marine system?

Stocking your marine system doesn't have to be challenging. By choosing peaceful, hardy fish and maintaining the water quality, you can build a thriving saltwater ecosystem.

Check out our full range of marine products to get started with today.