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If you are in the market to add a fish tank to your home, you might be wondering about how the aquarium might fit into your existing room layout. Fish tanks are available in almost any size you can imagine, ranging from tiny 2-gallon shelf tanks to massive 200-gallon tanks that require their own piece of furniture.

There are obvious benefits to choosing a large aquarium, the main point being that you will be able to raise more and larger fish. When planning your new addition, you will have more to consider than just the footprint of your aquarium. The weight of your aquarium will also play an important factor in deciding what size you can accommodate. Fish tanks are surprisingly heavy, and you will definitely not want to place a heavy tank on a table or shelf that might not be able to support the weight. If a table collapses under your tank, you will be in for some serious water damage, not to mention the loss of your aquarium investment.

So, how much do fish tanks weigh? To start, 1-gallon of room temperature water will weigh roughly 8.34lbs. The remaining weight will depend on many variables, such as your aquarium size, whether it is glass or acrylic, and your choice of substrate, and decorative items.

However, the standard rule of measure is that your aquarium will weigh around 10 pounds per gallon (this measure is meant to include the tank and water, and nothing else). This might be sounding extra heavy, but likely unsurprising if you have ever carried a gallon bucket of water or lifted an empty glass fish tank. This is definitely something important to plan for, especially if you are looking to place a large 100+ gallon tank- which will weigh over 1,000 pounds. You will want to make sure that you have the proper furniture and floor support to take on a fish tank of that size. To help you better imagine what size aquarium you can accommodate based on weight, let’s take a look at what you might need to support small, medium, and large-sized aquariums at home.

Small Aquariums

Small aquariums are probably the largest range since there are tiny desktop tank kits being sold in the 2-gallon or less range. These ultra-small tanks are not recommended for beginners, despite what you might be inclined to think, because it is extremely difficult to maintain healthy water quality with such a small volume. Because of this, a small tank can also be considered a 5, 10, or 15-gallon tank- sizes most often recommended for beginners.

Tank Size (Gallons)Estimated Weight with Water Only (lbs)
2 gallons20+ lbs
5 gallons50+ lbs
10 gallons100+ lbs
15 gallons150+ lbs

At this stage, you should be fine with placing one of these smaller-sized fish tanks anywhere in your home. The ones at the larger end of the spectrum (10-15 gallons) would likely need their own stand or dedicated table- which will add to the total weight in that area. However, this is likely still not enough weight to cause any structural problems. There are many items of furniture that weigh more than a small aquarium, so any one of these sizes could be used on the upper floor of your home without being worried about stability. The weight estimates for these sizes are likely on the lower end because you will also have to add in the weight of the substrate, the lighting and extra hardware, and any additional items you place in the tank.

Medium Aquariums

Medium-sized aquariums start to get into heavy-lifting territory, though you still won’t likely have to worry about structural problems in your home. A medium aquarium would likely fall in the range of 20-40 gallons. At this stage, you are looking at aquariums that will require their own furniture or stand set up. There are plenty of out-of-the-box kits available from fish supply stores that will come with a stand that is suitable for the weight of the tank.

Tank Size (Gallons)Estimated Weight with Water Only (lbs)
20 gallons200+ lbs
25 gallons250+ lbs
30 gallons300+ lbs
40 gallons400+ lbs

Large to Extra Large Aquariums

The larger tanks, which are often meant to house large species and reef tanks and become a prominent display in your home, require some special thought before setting up. In addition to being extremely heavy once full, these tanks are also extremely heavy when they are empty. You will likely need some outside help to move the tank to the desired location. Also, the substrate required to fill these large tanks- and also the added weight of live rock and concrete anchors for coral in the case of reef tanks- means you are looking at a much larger weight investment.

Tank Size (Gallons)Estimated Weight with Water Only (lbs)
55550+ lbs
65650+ lbs
75750+ lbs
90900+ lbs
1251200+ lbs
1501500+ lbs

As you can see, at these sizes the weight can go up to staggeringly high numbers. For these tanks, you will want to consult with a professional to evaluate the condition of your home structure. Which direction do your supports run? What type of floors do you have? What will be the added weight of the aquarium cabinet?

For many people, these tanks are a great option for the ground floor, where there is a better chance of having sturdy support. Finished basements are also a great idea since they have a solid concrete foundation to support the extra load. It’s also worth mentioning that keeping your large fish tank on the ground floor means less muscle work when moving in the tank, furniture, and water for the setup process. The less time spent navigating stairs when maneuvering a tank of this stature, the better!

Custom Aquariums

Due to the intense weight and support requirements for larger tanks, many people opt for custom aquariums. Working with a professional to analyze your space and create a unique tank that fits your layout can be a great way to maximize your tank size without risking serious damage. Custom aquariums can come in all sorts of unique sizes and shapes, and often are built into the home in such a way that they are guaranteed to be structurally sound.

Other Factors

There are a few other factors you should consider when trying to achieve an ideal weight for your aquarium. If you are trying to shave off some weight in order to fit an aquarium into your home, consider some of these options.

The type of material that your aquarium is made of will impact the weight of the overall tank. For example, acrylic tanks weigh a little bit less than glass and are often very similar visually. Also, consider the thickness of the tank. While thicker glass can make your aquarium sturdier and safer, it also makes it heavier! It’s a good idea to compare the individual measurements of each tank that you are considering before you make your purchase.

The substrate that you choose will also impact the weight of your aquarium. Coarse gravels and large stone substrates are often- but not always- heavier than fine-grain sand or soil. That being said, you might need more of the fine substrate to cover the bottom of your tank than you would for large gravel. Most substrates are sold by weight, so you will be able to factor this into your decision from the onset. There are also some online calculators that you can use to estimate how much substrate you will need, and the probable weight. The usual recommendation for substrate depth is around 2 inches.

Freshwater and saltwater will also have slightly different weights from one another. This stems mostly from the fact that saltwater- especially reef- setups are going to require much more equipment than a basic freshwater tank. For example, a basic reef tank will need to accommodate heaters, chillers, protein skimmers, special grow lights, and more. All of the added equipment is likely to add some more space and weight to your aquarium.


When planning to add an aquarium to your home, it is crucial to consider the total weight of your setup before purchasing any equipment. Aquariums can become heavy very quickly, and if your chosen location can’t safely support the weight of your tank, you will risk damage to your home and fish. Smaller aquariums are great for most spaces, and there are a variety of fish tank stands and cabinets that are available from fish supply stores that accommodate all of the most common fish tank sizes.

If you are acquiring a large fish tank, it’s always a good idea to consult a professional prior to installation, just to be sure the location can handle the added weight of the tank. Since a 180-gallon fish tank can weigh over a ton, it is definitely worth investigating the structural integrity of the surrounding room and floor surface. Luckily, there are also plenty of options for custom fish tanks, which are a great choice for those looking to optimize their space for the best tank possible. Taking time to consider the weight of your fish tank before installation will be well worth it for a safe and sustainable home aquarium.


Hi, my name is Jordan. I've been in the fishkeeping hobby since my childhood. Welcome to my blog where I help fishkeepers enjoy the hobby by offering free guides, advice, & product reviews. Read more...