Beginner Quick-Start Guide
Everything you need to know to start your first marine aquarium. From choosing the right fish to cycling your tank, this guide walks you through each step.
Best Beginner Fish
These peaceful, hardy species are ideal for new marine aquarists. They tolerate a range of conditions and get along well with other community fish.
Adorned Wrasse
Halichoeres cosmetus
African Rabbitfish
Siganus luridus
Agile Chromis
Chromis agilis
Arabian Damselfish
Neopomacentrus xanthurus
Axilspot Hogfish
Bodianus axillaris
Banggai Cardinalfish
Pterapogon kauderni
Barber Goby
Elacatinus figaro
Barred Grunt
Conodon nobilis
Barrier Reef Chromis
Chromis nitida
Barspot Cardinalfish
Apogon retrosella
Bennett Toby
Canthigaster bennetti
Bicolor Blenny
Ecsenius bicolor
Bicolor Foxface
Siganus uspi
Big Eye Soldierfish
Myripristis berndti
Black Axil Chromis
Chromis atripectoralis
Black Chromis
Chromis xanthura
Black Clown Goby
Gobiodon atrangulatus
Black Combtooth Blenny
Ecsenius namiyei
Black Ray Goby
Stonogobiops xanthorhinica
Black-Bar Chromis
Chromis retrofasciata
Blackbelt Cardinalfish
Apogon nigrofasciatus
Blackcap Basslet
Gramma melacara
Blackline Fang Blenny
Meiacanthus nigrolineatus
Blackspot Blenny
Ecsenius stictus
Blackstripe Cardinalfish
Ostorhinchus nigrofasciatus
Blue Axil Chromis
Chromis caudalis
Blue Chromis
Chromis cyanea
Blue Green Chromis
Chromis viridis
Blue Gudgeon Dartfish
Ptereleotris heteroptera
Blue Spotted Puffer
Canthigaster solandri
Blue-eyed Cardinalfish
Apogon compressus
Blue-lined Rabbitfish
Siganus doliatus
Bodianus Hogfish
Bodianus bimaculatus
Bridle Cardinalfish
Ostorhinchus semicinctus
Broadstripe Cardinalfish
Ostorhinchus angustatus
Broadstripe Goby
Elacatinus prochilos
Buan Sand Goby
Amblygobius buanensis
Bundoon Blenny
Ecsenius bundoon
Canary Fang Blenny
Meiacanthus oualanensis
Chagos Clownfish
Amphiprion chagosensis
Chalk Bass Goby
Serranus tortugarum
Clown Goby (Citrinus)
Gobiodon citrinus
Clown Wrasse
Halichoeres maculipinna
Convict Tang
Acanthurus triostegus
Cooktown Cardinalfish
Ostorhinchus cookii
Copper Cardinalfish
Apogon aureus
Coral Rabbitfish
Siganus corallinus
Crown Squirrelfish
Sargocentron diadema
Diadem Dottyback
Pictichromis diadema
Disco Blenny
Meiacanthus smithi
Doederlein Cardinalfish
Ostorhinchus doederleini
Dottyback Hogfish
Bodianus neilli
Doublebar Cardinalfish
Apogon taeniophorus
Dragon Goby
Amblygobius phalaena
Dusky Cardinalfish
Phaeoptyx pigmentaria
Ember Blenny
Ecsenius ember
Eyelash Blenny
Cirripectes chelomatus
Eyeshadow Cardinalfish
Apogon perlitus
Fairy Wrasse (Filamented)
Paracheilinus filamentosus
Fairy Wrasse (Flame)
Cirrhilabrus jordani
Fairy Wrasse (Lineatus)
Cirrhilabrus lineatus
Fairy Wrasse (Lubbock's)
Cirrhilabrus lubbocki
Fairy Wrasse (Rhomboid)
Cirrhilabrus rhomboidalis
Firefish Goby
Nemateleotris magnifica
Five Lined Cardinalfish
Cheilodipterus quinquelineatus
Flame Cardinalfish
Apogon maculatus
Flaming Blenny
Cirripectes castaneus
Fowleria Cardinalfish
Fowleria isostigma
Foxface Rabbitfish
Siganus vulpinus
Frostfin Cardinalfish
Ostorhinchus hoevenii
Gold-spotted Rabbitfish
Siganus punctatus
Goldbelly Cardinalfish
Ostorhinchus apogonides
Golden Foxface
Siganus guttatus
Green Clown Goby
Gobiodon histrio
Greenband Wrasse
Halichoeres bathyphilus
Half & Half Chromis
Chromis dimidiata
Half-and-Half Chromis
Chromis iomelas
Harlequin Bass
Serranus tigrinus
Hector's Goby
Koumansetta hectori
Highfin Blenny
Atrosalarias fuscus
Horned Blenny
Parablennius intermedius
Horned Rockskipper
Andamia tetradactyla
Kamohara Blenny
Meiacanthus kamoharai
Klein's Butterflyfish
Chaetodon kleinii
Lagoon Shrimp Goby
Cryptocentrus cyanotaenia
Lawnmower Blenny
Salarias fasciatus
Linear Blenny
Ecsenius lineatus
Link Goby
Amblygobius linki
Longspine Cardinalfish
Zoramia leptacantha
Luther Prawn Goby
Cryptocentrus lutheri
Magnus Goby
Amblyeleotris sungami
Masked Rabbitfish
Siganus puellus
Melanurus Wrasse
Halichoeres melanurus
Meteor Cardinalfish
Archamia zosterophora
Midas Blenny
Ecsenius midas
Molly Miller Blenny
Scartella cristata
Moluccan Cardinalfish
Ostorhinchus moluccensis
Nebulous Wrasse
Halichoeres nebulosus
Neon Goby
Elacatinus oceanops
Oblique-banded Cardinalfish
Archamia bleekeri
Ocellaris Clownfish
Amphiprion ocellaris
Ocellate Cardinalfish
Apogon notatus
One Spot Blenny
Crossosalarias macrospilus
One Spot Foxface
Siganus unimaculatus
Orange Skunk Clownfish
Amphiprion sandaracinos
Orangespotted Blenny
Blenniella chrysospilos
Orangethroat Cardinalfish
Apogon cyanosoma
Orbiculate Cardinalfish
Sphaeramia orbicularis
Pajama Cardinalfish
Sphaeramia nematoptera
Pastel Green Wrasse
Halichoeres chloropterus
Peacock Blenny
Salarias pavo
Pearly Cardinalfish
Ostorhinchus fleurieu
Peppered Squirrelfish
Sargocentron punctatissimum
Percula Clownfish
Amphiprion percula
Pink Cardinalfish
Apogon porphyreus
Pink Skunk Clownfish
Amphiprion perideraion
Pink-Speckled Shrimp Goby
Cryptocentrus leptocephalus
Possum Wrasse
Wetmorella nigropinnata
Pretty-Fin Cardinalfish
Pristiapogon kallopterus
Purple Chromis
Chromis scotti
Purple Firefish
Nemateleotris decora
Randall's Goby
Amblyeleotris randalli
Red Belted Cardinalfish
Apogon townsendi
Red Margin Shrimp Goby
Amblyeleotris rubrimarginata
Red Sea Mimic Blenny
Ecsenius gravieri
Red Stop Light Cardinalfish
Apogonichthys hyalinus
Redhead Wrasse
Halichoeres rubricephalus
Ring-tailed Cardinalfish
Ostorhinchus aureus
Royal Gramma
Gramma loreto
Sailors Choice
Haemulon parra
Sawcheek Cardinalfish
Apogon quadrisquamatus
Scarface Blenny
Cirripectes stigmaticus
Schooling Bannerfish
Heniochus diphreutes
Scissortail Dartfish
Ptereleotris evides
Seale's Cardinalfish
Apogonichthyoides sealei
Seaweed Blenny
Parablennius marmoreus
Segmented Sailfin Blenny
Salarias segmentatus
Sharknose Goby
Elacatinus evelynae
Sharpnose Puffer
Canthigaster rostrata
Sharptail Eel
Myrichthys breviceps
Shortstripe Goby
Elacatinus chancei
Skunk Clownfish
Amphiprion akallopisos
Slippery Dick
Halichoeres bivittatus
Smallmouth Grunt
Haemulon chrysargyreum
Spanish Grunt
Haemulon macrostomum
Speckled Squirrelfish
Sargocentron cornutum
Spot-tail Dartfish
Ptereleotris uroditaenia
Spotfin Cardinalfish
Jaydia striata
Spotlight Goby
Elacatinus louisae
Starry Goby
Asterropteryx semipunctata
Steinitz Goby
Amblyeleotris steinitzi
Striped Cardinalfish
Ostorhinchus fasciatus
Striped Fang Blenny
Meiacanthus grammistes
Tailspot Blenny
Ecsenius stigmatura
Tailspot Squirrelfish
Sargocentron caudimaculatum
Talbot's Damselfish
Chrysiptera talboti
Threadfin Cardinalfish
Apogon leptacanthus
Tiger Snake Eel
Myrichthys maculosus
Timor Wrasse
Halichoeres timorensis
Tomini Tang
Ctenochaetus tominiensis
Two Spot Hawkfish
Amblycirrhitus bimacula
Two-barred Rabbitfish
Siganus virgatus
Two-Spot Bristletooth Tang
Ctenochaetus binotatus
Two-tone Wrasse
Halichoeres prosopeion
Twobelt Cardinalfish
Archamia fucata
Twospot Cardinalfish
Archamia biguttata
Twotone Chromis
Chromis margaritifer
Vagabond Butterflyfish
Chaetodon vagabundus
Vanderbilt's Chromis
Chromis vanderbilti
Violet Squirrelfish
Sargocentron violaceum
White Bonnet Clownfish
Amphiprion leucokranos
White Grunt
Haemulon plumierii
White-Tail Bristletooth Tang
Ctenochaetus flavicauda
Whitestar Cardinalfish
Apogon lachneri
Y-Bar Watchman Goby
Cryptocentrus fasciatus
Yellow and Purple Wrasse
Halichoeres leucoxanthus
Yellow Blenny
Ecsenius flavipes
Yellow Cardinalfish
Ostorhinchus luteus
Yellow Chromis
Chromis analis
Yellow Clown Goby
Gobiodon okinawae
Yellow Coris Blenny
Ecsenius ops
Yellow Coris Wrasse
Halichoeres chrysus
Yellow Watchman Goby
Cryptocentrus cinctus
Yellow-Axil Chromis
Chromis xanthochira
Yellow-striped Cardinalfish
Ostorhinchus cyanosoma
Yellowcheek Wrasse
Halichoeres cyanocephalus
Yellowfin Cardinalfish
Ostorhinchus chrysopomus
Yellowhead Wrasse
Halichoeres garnoti
Zebra Dartfish
Ptereleotris zebra
Zigzag Wrasse
Halichoeres scapularis
Recommended Tank Sizes
Bigger tanks are more forgiving for beginners because water parameters stay more stable. Here is what to expect at each size tier.
Nano
10–20 gal1–3 small fish
Great for a desk or bedroom. Limited stocking options but easy to maintain once established.
Small
30–40 gal4–6 fish
The most beginner-friendly size. Stable water parameters with room for a diverse community.
Medium
55–75 gal6–10 fish
Opens up more species options. Enough space for tangs and other active swimmers.
Large
90–125 gal10+ fish
Room for tangs, angels, and larger species. More forgiving water chemistry due to volume.
Water Parameters Basics
Maintaining stable water chemistry is the single most important factor in keeping marine fish healthy. Test your water at least weekly and aim for these ranges.
| Parameter | Ideal Range |
|---|---|
| Temperature | 76–80°F |
| Salinity | 1.023–1.025 sg |
| pH | 8.1–8.4 |
| Ammonia | 0 ppm |
| Nitrite | 0 ppm |
| Nitrate | <20 ppm |
| Alkalinity | 8–12 dKH |
First Tank Setup Checklist
Follow these steps in order. Patience during the cycling phase is the key to long-term success.
- 1
Research and plan
Decide on tank size, budget, and which species you want to keep. Allow 2–4 weeks for research.
- 2
Purchase tank and equipment
Get your tank, stand, heater, powerhead, protein skimmer, lighting, and test kit.
- 3
Set up tank with substrate and rock
Add live sand or aragonite substrate, arrange live rock to create caves and hiding spots.
- 4
Fill with saltwater and start cycling
Mix RO/DI water with marine salt to the correct salinity and begin the nitrogen cycle.
- 5
Test water parameters daily during cycle
Monitor ammonia, nitrite, and nitrate levels. The cycle typically takes 4–6 weeks to complete.
- 6
Add first hardy fish after cycle completes
When ammonia and nitrite read zero, introduce your first hardy species like clownfish or chromis.
- 7
Add fish slowly
Only add 1–2 new fish per week to avoid overloading the biological filter.
- 8
Maintain regular water changes
Perform 10–20% water changes weekly to keep parameters stable and remove excess nutrients.
Ready to explore?
Browse our full database of beginner-friendly fish to find the perfect additions to your new aquarium.
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