Looking for an aquarium that’s not too big, not too heavy, and not too small? Sounds like a 30-gallon saltwater tank may be the right fit for you and your space.
A 30-gallon saltwater tank has a few advantages over 10-gallon and 20-gallon tanks, including:
- A wider range of saltwater fish will be happy in a tank this size
- Greater stability over time (less dramatic swings in water parameters)
- Ability to keep a few more saltwater fish, invertebrates, and corals
While the volume is sufficiently larger than 10s and 20s, the dimensions of the 30-gallon are also compact enough to take up less space than the 55-gallon and larger tanks.
Typical 30-gallon tank dimensions
There are at least three popular and readily available saltwater tanks around 30 gallons in volume with different dimensions:
- 30-gallon “breeder” has the longest footprint of the three: 36 in. long x 18 in. wide x 12 in. deep. It is 6 inches longer and wider than the 20-gallon long, and the same height as the standard 10 and 20-gallon long
- 29-gallon is a tall tank that is 30 in. long x 12 in. wide x 18 in. high – that’s the same length and width as the 20-gallon long aquarium, but with an additional 6-inches in height.
- 32-gallon Biocube all-in-one tank kit, as the name implies (cube) is just about cuboid in shape with almost equal dimensions 20.25 in. long x 21.875 in. wide x 21.5 in. high, yielding the greatest volume while taking up the least wall-space in your room
| Length | Depth | Height | |
| 30-gallon breeder | 36 in. (91.4 cm) | 18 in. (45.7 cm) | 12 in. (30.5 cm) |
| 29-gallon | 30 in. (76.2 cm) | 18 in. (45.7 cm) | 18 in. (45.7 cm) |
| 32-gallon Biocube | 20.25 in. (51.4 cm) | 18 in. (45.7 cm) | 21.5 in. (54.6 cm) |
If none of those seem like the right size for the space you have available in your apartment or home, you may want to check out either a:
- 90-gallon tank
- 75-gallon aquarium dimensions, stocking levels and recommended fish
- 55 gallon tank guide
- 40 gallon aquarium
- 20-gallon saltwater tank and the best fish for that size
- 15 gallon saltwater tank sizes and fish
- 10-gallon tank
Selecting the best saltwater fish for a 30-gallon tank
The extra volume in a 30-gallon saltwater tank will allow you enough room to keep all of the fish types that are appropriate for a 10 or 20-gallon aquarium, plus several more.
What makes a saltwater fish great for a 30-gallon tank? In general, they share a few key attributes:
There are a few key attributes
The best saltwater fish for a 30-gallon tank is:
- Peaceful, not aggressive
- Relatively small in size—about 5-inches or less
- Slow swimming or likes to perch on rocks instead of zipping all around
36 Best saltwater fish for a 30-gallon tank (fish types and stocking levels)
| Saltwater fish type & number (7-9) | Alt 1: | Alt 2: | Alt 3 | Alt 4: | Alt 5: | Alt 6: |
| Clownfish (1 pair) | Ocellaris | Percula | Orange skunk | Pink skunk | ||
| Green chromis (1) | Instead of clown | |||||
| Dartfish (1) | Firefish | Purple Firefish | Zebra | Scissortail | ||
| Fancy goby (1) | Clown | Two Spot goby | Yasha | Court Jester | ||
| Cleaner goby (1) | Neon | Yellow line | Shark Nose | Hybrid | ||
| Small blenny or Fang blenny (1) | Tailspot | Two Spot blenny | Canary | Midas | Striped | Harptail |
| Cardinalfish (1) | Banggai | Yellow | Flame | |||
| Hawkfish (1) | Flame | Longnose | Falco | |||
| Fairy basslet (1), Chalk basslet (1), or Orchid Dottyback (1) | Royal gramma | Blackcap | Chalk basslet | Orchid dottyback | ||
| Jawfish (1) or Engineer goby (1) | Yellow-headed jawfish | Blue spot jawfish | Engineer goby |
- 1-2 small Clownfish of the same type ( Ocellaris, Percula, Orange skunk, or Pink skunk) or 1 Green chromis as an alternative to clownfish
- 1 Dartfish (Firefish, Purple firefish, Zebra, or Scissortail)
- 1 Fancy goby (Clown, Two spot, Yasha or Court jester)
- 1 Cleaner goby (Neon, Yellow line, Shark nose, or Hybrid)
- 1 Small blenny *(Tailspot, Two spot) or 1 Fangtooth blenny (Canary, Midas, Striped, Harptail)
- 1 Cardinalfish (Banggai, Yellow, or Longfin)
- 1 Hawkfish (Flame, Longnose, or Falco)
- 1 Fairy Basslet* (Royal gramma, or Blackcap), Chalk basslet OR 1 dottyback (below)
- 1 Aiptasia-eating filefish
- 1 Orchid Dottyback* (be careful of aggression)
- 1 Jawfish (Yellowhead or Blue spot jawfish)
- 1-2 Engineer gobies
* A fang blenny, orchid dottyback, and basslet should probably not be housed together. There are no guarantees, when it comes to predicting fish behavior, however, these three are relatively known to be quarrelsome. It is best to pick only 1 from this list of 3 different types.
Or you could keep a damselfish-only 30-gallon saltwater aquarium
I don’t admit this all that often, but I love damselfish. They are gorgeous, available in stunning colors, hardy, and inexpensive. The world loves damselfish, which is why a few different species are imported as the top 20 most popular saltwater fish, but the big problem with damselfish is that they are often a problem when kept with other fishes.
In a way, the damselfishes are like African Cichlids—which is quite possibly a fantastically helpful comparison to a great way to keep them. Why not keep a damselfish-only 30-gallon tank stocked with 7-9 damsel species of your choice?
- Azure
- Blue
- Blue Devil
- Bluefin (actually mostly white with yellow…ironic)
- Blue Velvet
- Domino
- Three Stripe or Four Stripe
- Yellowtail
Credit goes to Gary Parr from the ReefThreads Podcast for the inspiration for that idea.
Equipment needed for a 30-gallon saltwater tank
To care for the saltwater fish in your 30-gallon tank, you will need the following equipment:
All in one aquarium
If you get an all-in-one 30-gallon saltwater tank, like the Biocube 32, it will come with everything you need, except a 100-watt heater. Then again, you may want to check out these Best BioCube 32 Upgrades to really kick it up a notch.
Build your own saltwater tank
If you want to build your own tank, you have the option to customize the equipment and generally, save some money, here is what you need:
- A 30-gallon saltwater tank (buy this at a local store, don’t pay for ridiculous shipping)
- A lid to prevent fish from jumping out when startled–believe it or not, this happens A LOT and especially in the species recommended here
- An air pump & airline tubing or a Powerhead pump, like the Vortech, for water flow.
- Either sponge, hang-on-back, canister, or Live Rock to help with biological filtration
- 100 Watt heater
- If you’re planning to keep corals, you will want a reef tank quality LED light, like Aqua Illumination Prime 16, Kessil, or even the ViparSpectra light.
- If you’re not planning to keep corals yet, there are less expensive aquarium LED lights by AQUANEAT, HYGGER, and NICREW that will work just fine—I use one of those models on my fish-only quarantine tank and the 10-gallon fish-only tank (yes, I have too many tanks)
A few important related topics to consider
I hope this article gave you a few ideas about some of the best fish for a 30-gallon saltwater tank. As you know, this is just the beginning, there are lots of other topics to cover. Here are a few other very important articles to help you have success with your new saltwater tank:
- How to make saltwater?
- How to set up a saltwater tank?
- How much live rock do you need?
- The 9 Most important water parameters
- Selecting the best reef tank salt mix
Other stocking options
Fish are possibly the easiest and most readily available animals you can keep in your 30-gallon saltwater tank, but they are far from the only thing you can keep. Liven up your tank with:
- Exploring the different coral types
- Finding a fantastic cleaner shrimp
- Learning about Cerith snails and clean up crews
Other size saltwater tanks
If you want to find the best saltwater fish for tanks that are other sizes besides 30 gallons, check out these other great stocking guides:
- 10-gallon tank
- 15- gallon aquarium
- 20-gallon tank
- 40-gallon stocking guide
- 50-gallon tanks
- 55-gallon tank size and stocking guide for saltwater
- 75-gallon aquarium size and saltwater fish guide
- 90-gallon aquarium: best fish options
- 100-gallon saltwater tank fish recommendations
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