Whether you’re setting up your first aquarium or upgrading to a new size, one of the most overlooked — yet critical — considerations is how much your fish tank weighs. This might not seem like a big deal at first, especially when dealing with smaller tanks like a 30-litre setup. But once you factor in the weight of water, substrate, decorations, and equipment, even a relatively modest tank can become surprisingly heavy.
Knowing the total weight of your aquarium is important for several reasons. First, it helps you choose a suitable stand or surface to place it on — one that can safely support the full load. Second, it ensures you’re not putting unnecessary stress on floors, especially in apartments or older homes. And finally, understanding the weight can help with transportation, placement, and long-term maintenance planning.
This guide is perfect for new aquarium owners, hobbyists, aquascapers, and even experienced fishkeepers who are working with limited space or specific structural concerns. Whether you’re planning a freshwater setup or a small planted tank, understanding what you’re dealing with weight-wise will save you time, effort, and potentially costly mistakes.
So, how heavy is a 30-litre fish tank? Here’s the quick answer:
-
Empty tank weight: Roughly 5–7 kg, depending on the material (glass or acrylic).
-
Filled tank weight: With water alone, that’s 30 kg (since 1 litre of water weighs about 1 kg). Add substrate, rocks, decorations, and equipment, and the total can range between 35–45 kg or more.
In the sections ahead, we’ll break this down in more detail and provide tips on how to manage and plan for your tank’s full weight safely.
Understanding Tank Volume vs Weight
When shopping for or setting up an aquarium, it’s easy to focus on volume — often listed in litres or gallons — without fully understanding how that translates into actual weight. But the two are closely linked, and knowing the difference is essential to ensure your tank is safe and properly supported.
Let’s start with the basics:
Volume refers to how much space a tank can hold — in this case, 30 litres of water. Weight, on the other hand, is how heavy that water (and everything else inside the tank) is. The key thing to remember is that 1 litre of water weighs approximately 1 kilogram (or about 2.2 pounds). So, if your tank holds 30 litres, that’s already 30 kilograms (66 pounds) of water alone — and that doesn’t include anything else.
Now, add in the weight of the tank itself. Most 30-litre aquariums are made of either glass or acrylic. Glass tanks are heavier but more scratch-resistant and stable. A glass 30-litre tank typically weighs around 5–7 kg (11–15 lbs) when empty. Acrylic tanks, on the other hand, are much lighter — often weighing about half as much as glass — but they’re more prone to scratches.
When filled, the total weight of a 30-litre glass tank, including water, will be in the range of 35–45 kg (77–99 lbs) once you include decorations, substrate, and gear.
Understanding the conversion from volume to weight is key for safety and setup. It affects where you place the tank, what stand or cabinet you use, and even whether your floor can handle the load, especially in older homes or apartments.
In the next section, we’ll break down the filled weight of a 30-litre tank in more detail.
How Much Does a 30-Litre Fish Tank Weigh?
Understanding the actual weight of a 30-litre fish tank — both empty and fully set up — is essential for choosing the right location and stand, and for ensuring safety in your home.
Empty Tank Weight
When it comes to the empty tank, the weight largely depends on the material used. Most small aquariums are made from either glass or acrylic.
-
Glass tanks are more common due to their clarity and scratch resistance. A 30-litre glass tank typically weighs 5 to 7 kilograms (11–15 pounds) when empty.
-
Acrylic tanks, while less common in this size, are considerably lighter — usually 2 to 4 kilograms (4.5–9 pounds) — and are easier to move. However, they can scratch more easily and may warp over time if not properly supported.
Filled Tank Weight
When filled with water, the weight increases significantly. Since 1 litre of water weighs 1 kilogram, just the water in a 30-litre tank will weigh 30 kilograms (66 pounds).
But that’s not the whole picture.
When you set up your tank, you’ll likely add:
-
Substrate (gravel or sand): adds 2–5 kg.
-
Decorations: rocks, driftwood, plants — around 1–3 kg.
-
Equipment: filters, heaters, lighting gear — another 1–2 kg.
Add all of that together, and your fully stocked 30-litre aquarium could weigh between 35 to 45 kilograms (77 to 99 pounds), possibly more depending on your setup.
This total weight should guide where you place your tank. It’s crucial that the surface or stand can support the full load evenly to avoid tipping, cracking, or long-term damage to both your tank and your furniture.
Factors Affecting Total Weight
The total weight of a 30-litre fish tank doesn’t just come from the water itself. Several other components contribute to the overall load, which is important to consider when setting up your aquarium in your home.
Type and Amount of Substrate
Substrate is one of the first things you’ll need to decide on when setting up your tank. Whether you choose gravel, sand, or another material, it will add significant weight. The amount you use also makes a difference. A thin layer of substrate might weigh around 2 kilograms, but if you opt for a thicker layer or denser material like gravel, you could add up to 5 kilograms or more. Substrate is essential for supporting plant life and helping filter the water, so its weight will vary based on your aquascaping needs. In case you are interested in this type of article, here is our top recommended article: What is the Best Size Tank for a Home Aquarium?
Rocks, Plants, and Décor
Adding natural elements like rocks, driftwood, and plants can contribute both to the aesthetics of the tank and to its weight. Rocks, for example, are often dense and heavy, and the amount you add will depend on your design preferences. The weight from these decorations can range from 1 to 5 kilograms depending on the size and type.
Live or artificial plants will also add to the weight. Live plants require additional consideration as their weight can change when they grow and absorb water, but for initial setup, plants typically contribute just 1 to 2 kilograms.
Filters, Heaters, and Other Equipment
While they don’t add a huge amount of weight individually, equipment like filters, heaters, and lighting still play a role in the overall weight. Together, these elements could add anywhere from 1 to 3 kilograms to the total load.
Type of Stand or Surface Requirements
The stand or surface where the tank sits can also impact how weight is distributed. A sturdy stand designed to support an aquarium will be built to handle the tank’s full weight, including all the water, substrate, décor, and equipment. The stand or surface must be level and strong enough to prevent any shifting or damage.
Why Tank Weight Matters
Understanding the weight of your 30-litre fish tank is crucial not only for a safe setup but also for ensuring long-term stability. Even though a 30-litre tank may seem small, when it’s filled with water, substrate, décor, and equipment, the total weight can add up quickly, requiring careful consideration of where and how to place your aquarium.
Safety Considerations for Floors and Furniture
One of the primary concerns when setting up an aquarium is the potential for damage to your floors or furniture. Aquariums, especially when filled, can be extremely heavy, and placing a 30-litre tank on a surface that isn’t designed to handle the weight could result in cracks, warping, or even structural failure. Floors, especially in older buildings or apartments, may not have the capacity to bear such weight over time, which could lead to damage or worse — an unexpected collapse.
For furniture, it’s essential to ensure that the cabinet or stand supporting the tank is specifically made for aquariums. Regular furniture like bookshelves or TV stands may not have the necessary support. Always double-check the weight capacity of the stand or surface before setting your tank down.
Placement Recommendations
When choosing a location, avoid placing your 30-litre tank on surfaces that are too weak or uneven. Carpets, soft flooring, or thin plywood are not suitable for supporting a full aquarium. Look for solid, level surfaces such as a sturdy, flat table or an aquarium stand.
It’s also important to consider the location in terms of accessibility and safety. Avoid placing the tank near windows where sunlight could cause algae growth, or in high-traffic areas where it might get knocked over.
Tips for Distributing Weight Safely
To ensure your tank stays stable and secure:
-
Always use an aquarium stand designed to distribute weight evenly across the surface.
-
If you place your tank on a shelf or custom stand, make sure it is reinforced to handle the added weight.
-
For extra protection, consider using a foam mat or cushioning material beneath the tank to help absorb weight and reduce stress on the surface.
By carefully considering these factors, you can ensure that your 30-litre aquarium remains safe and stable throughout its use.
Conclusion:
Understanding the weight of your 30-litre fish tank is a crucial part of ensuring a safe and successful aquarium setup. From the empty tank to the fully stocked setup, the weight can quickly add up, with water, substrate, decorations, and equipment all contributing to the overall load. By knowing the weight of your tank, you can make informed decisions about where to place it, how to properly support it, and ensure that your flooring and furniture can handle the load. This knowledge helps prevent costly mistakes, such as placing your tank on an unsuitable surface, which could lead to potential damage or accidents.
Remember that a solid, level surface and a properly designed aquarium stand are key to ensuring the stability of your setup. Taking the time to account for the full weight of your tank, including all components, will ensure the safety of your home and the health of your aquatic life. Whether you’re a first-time aquarium owner or a seasoned hobbyist, careful planning and understanding of weight considerations will help you enjoy your aquarium for years to come.
