Aquarium Weights With Sizes And Dimensions

If you are planning to purchase a new saltwater aquarium, it’s important to know the weight and size of the tank you are dealing with ahead of time. Many things can affect what size and weight of aquarium you decide on keeping such as space available in your room, the type of stand you plan to use, the type of livestock you plan to have, and performing maintenance will all play a role.

Tall tanks are never fun to clean!

It’s important to note that all aquariums, when filled with water, are very heavy. This can definitely be a concern if you plan to move the tank around. Obviously, you don’t want to move the tank with water in it, therefore it can be quite tedious to drain a large tank and have it ready to move into a new location. You may decide that a smaller and lighter tank will work better for your living space.

In this article, I will show you the weights, sizes, and dimensions of glass aquariums as they sit empty and filled with water placing them into 3 categories. Small, medium, and large. You can use the charts below to see the effect of aquarium size has on the weight.

There are a few variables that determine the weight of the aquarium. Glass type and thickness, and type of water being used all play a role. For example, freshwater with a specific gravity of 1.000 weighs 8.4 lbs. If the specific gravity of water changes, so does the weight. SG 1.025 water will weigh 8.6 lbs. ( 1.025 x 8.4) 

For the purpose of this article, I will assume you are planning to set up a saltwater tank with a specific gravity of 1.025 @ 8.6 lbs/gal

The aquarium empty weights are determined by the manufacturer. 

Small aquariums – Up to 15 gallons

These numbers are rounded up or down to the closest weight.

Medium Aquariums – 20 to 40 gallons

These numbers are rounded up or down to the closest weight.

Large aquariums – 55 to 225 gallons

These numbers are rounded up or down to the closest weight.

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Something else to keep in mind when thinking about the weight of your tank when filled. The numbers given when the tank is filled with water do not include the weight of rocks, sand, equipment, and any other decorations you may have in the tank.

As you can see with the medium and large-sized tanks, they are very heavy when both empty and filled. It becomes quite a difficult chore to move around a large tank. If you have a 180-gallon tank which weighs over a ton when filled with saltwater and wish to move it, you will most likely need other tanks or storage containers to keep the water until you move the tank and refill it. If you are using RODI water, which you should, it can get very time consuming and costly to throw away the water just to move a tank then remake a new batch. It’s just not worth doing. Therefore moving a large, heavy tank is just not possible for some people so it’s important to choose your tank wisely in the beginning.

Of course, if you have a smaller tank, then this is not really a concern. Small tanks are so much easier to move around and only take a fraction of the time and effort required to move a large tank. If you only have a small section of the wall in your room, then a smaller tank will be your only option. Perhaps a nano tank is a great option like the Coralife Biocube that I have on a very small wall in my living room. You can read more on that by clicking the link or image.

The other advantage of using smaller tanks would be the cost. They are considerably cheaper to buy versus large tanks.

You can also use the above numbers to help you decide on specific gear and accessories you may need. For example, if you choose to use a 75-gallon tank, you will need around 75 lbs of rock and substrate to fill a 48″ x 18″ x 21″ tank. You will also need to match wavemakers or powerheads, lighting, and filtration that is suitable for that tank size. Also, remember that large tanks will require multiple heaters if the tank’s water volume is large.

Another consideration when choosing a tank size and weight will be the stand you decide to use. Smaller tanks that are lighter can be placed on a sturdy cabinet or end table. Medium and larger sized tanks will need a proper aquarium stand that can support the weight and dimensions of the tank. You don’t want a stand that doesn’t support the edges of the tank properly. I have seen many tanks that are overhanging the ends of the stand and that is just a disaster waiting to happen.

If you are using a 125-gallon tank, make sure to support it with a stand that is suitable for 72″ x 18″ x 21″ and keep in mind this tank will weigh around 1400 lbs when filled with water.


How thick is aquarium glass?

Aquarium glass can vary from 1/4″ up to 3/4″ or more depending on the size and manufacturer.

How do I calculate how many gallons my tank is?

The easiest way to do this is to multiply the dimensions of your tank together. Then take the result and divide by 231.

How do I calculate how many Liters are in an aquarium?

You can convert your tank size in gallons to liters by multiplying the gallons by 3.78541 10-gallon tank x 3.78541 = 37.8541 Liters