75 vs 90 Gallon Aquarium

75 vs 90 Gallon Aquariums


Trying to choose a fish tank can be a challenge, and because these can be pretty expensive, it’s important to get it right the first time around. The size of tank that you need will depend upon the livestock that you wish to add to it and the setup that you want to build.

A 75 gallon aquarium is a good size for most beginners, because it is relatively small and will not be too difficult to maintain. A 90 gallon aquarium is great if you want to size up a bit, have a slightly wider variety of stock, and a little more of a challenge. Choose carefully between these two popular sizes.

You need to think hard about what sort of setup you wish to achieve, how many fish you want and what species you plan to keep, and the space that you have before you choose an aquarium.

Is A 90 Gallon Fish Tank Big?

A 90 gallon fish tank is pretty large. It holds about 108 liters of water, and it’s the recommended size if you want to keep bigger fish, such as goldfish or cichlids. If you have a smaller tank, you should opt for the smallest species of fish so that you don’t overcrowd them. A 90 gallon fish tank:

  • Weighs between 400 and 500 pounds
  • Is generally made of glass, but could be acrylic or metal
  • May be spherical or rectangular
  • Tends to cost somewhere around $300, depending on the quality and where you purchase it from
  • Is usually about 21 to 24 inches deep
  • Will generally hold around 12 fish comfortably

You need to be aware of the limits on how many fish you can keep in the size of aquarium that you choose, because if you put too many fish in, you’ll run into various problems, such as unhappiness, aggression, disease, and the impossible task of keeping the tank clean. It is much better to have a tank that is stocked at comfortable levels.

You should also think about where you are going to put the tank and what it will stand on. You can purchase a commercial tank stand or build one, but you must make sure that you build one that is stable, strong enough to support the tank’s weight, and flat. The corners must be supported, because the water is going to weigh a lot!

Remember that a 90 gallon tank is going to be more work than a smaller tank. It takes longer to make changes to the water, it needs more cleaning, and if something goes wrong, it may be harder to fix. Any time that you increase the size of your aquarium, you are committing to a greater degree of work than if you have a small tank.

Is A 75 Gallon Fish Tank Too Big?

75 gallons isn’t generally considered too big, no. Most people who want to keep an aquarium would like to have a reasonable amount of size, and a 75 gallon tank allows you to keep multiple small fish comfortably and safely. This tank is particularly good for beginners, who may struggle with handling a bigger tank.

Estimates say that you can keep up to 25 fish in a 75 gallon tank, but note that these need to be a lot smaller than the fish you would keep in a 90 gallon tank. In general, you can house things like Silver Dollars, Neon Tetras, Zebra Danios, and German Blue Ram in a 75 gallon tank comfortably. If you put bigger fish in, you will only have room for 1 or 2.

Overcrowding is one of the biggest issues that people run into with a 75 gallon tank, because it’s tempting to fill all that space with beautiful fish – but this endangers the health of the fish and will result in lots of problems with keeping the tank parameters balanced. Your filtration system will not be able to keep up and algal blooms will occur.

As a rule of thumb, you should have one inch of fish per gallon of water at the most – and this refers to the fish’s adult size. Calculate the tank stock accordingly and resist the urge to overstock. A tank with fewer fish is easier to maintain, and the fish tend to be happier. If you are just starting out, stick closely to this guide.

How Wide Is A 90 Gallon Tank?

A 90 gallon tank can vary in width, but it is usually around 18 to 20 inches wide, so be aware of this if you need to find a place to put it. You must have a wide enough surface, and this usually involves building a dedicated aquarium stand with supports on all four corners. If you just balance the tank on a table, it may fall.

You can get 90 gallon tanks that are rounded or have a curved edge, and this will obviously affect the width, so there isn’t a fixed standard. A narrower tank will be a little longer or deeper to ensure the same quantity of water fits in it, but bear in mind that tanks cannot be too narrow, or they will not be strong enough to hold the water.

Before you buy a 90 gallon tank, you need to measure the available space that you have and make sure it will fit in your home. Don’t get a tank without measuring, as the width can be surprising, and you don’t want to find that your tank is too big. You should also think about where you are going to get a stand that will hold the tank’s weight and support all 4 corners.


A 75 gallon aquarium may be a better option if you are just entering the world of fish keeping, but a 90 gallon one will give you more space and flexibility. Be realistic about how much work you wish to take on before you set up either in your home, and opt for 75 gallons if you are just getting into the hobby.