Common Aquarium Sizes and Dimensions
A Helpful Guide to Common Black-Trim Aquarium Sizes and Dimensions
Black-trim glass aquariums are one of the most recognizable types of fish tanks, often lining the shelves of big box pet stores and serving as the entry point into the aquarium hobby for countless new aquarists. Their affordability and standardized sizing make them a convenient choice for building a first reef tank or testing the waters with a new marine setup.
When planning any saltwater aquarium, knowing the exact dimensions of your tank is essential. Whether you're working with limited space and need to find a tank that fits a specific spot, or you're mapping out equipment placement and lighting coverage, having accurate measurements helps ensure everything comes together smoothly.
Although black-trim aquariums are typically produced in standard sizes, the actual measurements can vary slightly from one manufacturer to another. The list below provides a general reference for some of the most common sizes and their typical dimensions. Always confirm the specific dimensions of your tank before purchasing equipment or designing your setup.
Standard Black-Trim Aquarium Dimensions
| Aquarium Size | Dimensions (L x W x H) |
|---|---|
| 2.5 Gallon | 12.25" x 6.25" x 8.125" |
| 5.5 Gallon | 16.25" x 8.4" x 10.5" |
| 10 Gallon | 20.25" x 10.5" x 12.6" |
| 15 Gallon | 24.5" x 12.5" x 12.75" |
| 20 Gallon (High) | 24.25" x 12.5" x 16.75" |
| 20 Gallon Long | 30.25" x 12.5" x 12.75" |
| 29 Gallon | 30.25" x 12.5" x 18.75" |
| 38 Gallon | 36.25" x 12.625" x 19.75" |
| 40 Gallon Breeder | 36.25" x 18.25" x 17" |
| 55 Gallon | 48.25" x 12.75" x 21" |
| 60 Gallon Breeder | 48.5" x 18.5" x 16" |
| 65 Gallon | 36.375" x 18.375" x 25" |
| 75 Gallon | 48.5" x 18.5" x 21.25" |
| 90 Gallon | 48.5" x 18.5" x 25.125" |
| 125 Gallon | 72.5" x 18.5" x 23.125" |
| 150 Gallon | 72.5" x 18.5" x 29.5" |
| 210 Gallon | 72.5" x 24.5" x 29.625" |
Frequently Asked Questions
What is a "Black-Trim" Aquarium?
A black-trim aquarium is a glass tank framed with black plastic molding around the top and bottom edges. This trim provides structural support and is commonly seen in standard-sized tanks sold at big box pet stores. These tanks are widely used for both freshwater and saltwater setups, including reef aquariums.
Are black-trim aquariums good for saltwater tanks?
Yes, many saltwater aquarists use black-trim aquariums to start their reef tanks. They're affordable, available in multiple sizes, and compatible with most equipment. However, some reef keepers eventually upgrade to rimless or low-iron glass tanks for better aesthetics and clarity.
Can I add a sump to a black-trim aquarium?
Yes, you can add a sump to most black-trim aquariums, but it typically requires some modifications. Standard black-trim tanks are not reef-ready out of the box, meaning they don’t come with built-in overflows or drilled drain holes. To use a sump, you can either:
- Drill the tank and install an internal overflow box with bulkheads and plumbing (non-tempered glass tanks only)
- Use a hang-on-back overflow box, which allows you to run a sump without drilling
Always confirm that the glass is not tempered before drilling, and consult with a professional or experienced hobbyist if you're unsure. Adding a sump is a great way to improve filtration, increase water volume, and hide equipment for a cleaner reef tank display.
Do all black-trim aquariums have the same dimensions?
Not always. While most follow standard sizing, actual dimensions can vary slightly between manufacturers. Always check the exact measurements before buying stands, lids, lights, or other accessories.
What size black-trim aquarium is best for a reef tank?
A 40-gallon breeder, 75-gallon, or 90-gallon black-trim tank is commonly recommended for reef aquariums due to their good dimensions for aquascaping and coral placement. These tanks offer enough depth and surface area to support stable water parameters and a wider variety of marine life. Larger tanks also expand your options when it comes to fish selection and bioload capacity. If you're aiming for a nano reef, the 20-gallon long is a popular choice thanks to its horizontal layout.
Not seeing the right aquarium size for you?
Explore our huge selection of aquariums, ranging from under 5 gallons to over 200 gallons. You'll find rimless, low-iron, and specialty tanks in both standard and unique dimensions to suit your needs.
Adam has been reef keeping since 2010 and got his start on the Bulk Reef Supply Customer Service team. He believes the best tanks are built around what you enjoy, not what’s trending. Adam is especially interested in simplifying the hobby, exploring the latest gear, and helping others focus on long-term success over chasing perfection.
Login and Registration Form