75 Gallon Aquarium Guide: Size, Stocking Ideas and More

A 75 gallon aquarium is large enough to keep a good variety of fish without it being too much for a beginner to maintain.

It can hold cichlids, catfish and even corals.

One of the best things about a tank this size is that it does not need as much equipment as a larger tank and it is much more affordable too.

Are you thinking about buying a 75 gallon tank?

Keep reading to learn everything you need to know about this tank, including dimensions, stocking advice, running costs and much more…

75 Gallon Saltwater Aquarium

All About 75 Gallon Aquariums

If you are used to keeping smaller tanks and would like to size up, then a 75 gallon is a great option for you.

With 75 gallons to work with, you have enough space to keep some of the larger and more territorial fish like Oscars and larger Plecos.

A 75 gallon tank is also one of the best Goldfish habitats.

These tanks come in many different shapes and sizes, from the basic rectangle to a tall cylindrical corner tank. They can even come in a pentagon or hexagon shape, which takes up less space in the room and provides a truly unique looking home for your fish.

A long rectangular tank is the most basic one that you can find and it can be made from either glass or acrylic.

Most 75 gallon aquariums will have base dimensions of about 48″x18″x21″.

However the exact dimensions will depend on their size and shape.

For example, corner aquariums are much wider than they are tall (they will measure 35″x35″x30″). A standing aquarium will be taller than it is long or wide (25″x25″x35″).

As for their weight, an empty aquarium can weigh up to 150 pounds. Once the tank is stocked it can weigh up to 850 pounds.

5 Benefits Of A 75 Gallon Aquarium

  1. A 75 gallon tank is the perfect balance between providing enough space and not requiring lots of maintenance. It does not need as much equipment to manage as larger tanks, nor does it need an especially powerful filter or heater. Still, it has enough space to keep many of the best aquarium fish and plants.
  2. If you do not live near a body of water, chances are that you have never had the opportunity to observe aquatic wildlife in their natural habitat. An aquarium lets you bring a miniature aquascape right into your home and provides an opportunity to learn about different kinds of aquatic ecosystems.
  3. A tank this size lets you add some diversity to your biotope by accommodating more fish and larger groups of your current fish. Many territorial fish need a large enough space to stay out of each other’s way, and even peaceful fish species need the space to swim around as much as they would like to.
  4. This tank is a great size and fits into most homes. Larger aquariums (150+ gallons) can take up an entire room in your house, but this tank can easily fit into a corner.
  5. Finally, this tank is fairly affordable to run and gives you the option of keeping larger fish like Cichlids and Gouramis.

75 Gallon Aquarium

How Much Does A 75 Gallon Fish Tank Cost?

Once you are certain that this is the right size aquarium for you, the price tag may be your very first roadblock.

Unfortunately a tank of this size is not cheap and the price goes even higher if you choose a higher quality tank.

If this is your first 75 gallon aquarium then it is probably best to get a cheaper glass aquarium. You should expect to pay between $130-$220 for a 75 gallon glass aquarium.

However they are often less durable than acrylic.

Acrylic aquariums are more durable but they are also more expensive.

A basic bare bones 75 gallon acrylic aquarium will cost $500-$800. A full setup with a stand and hood can run well over $1000. Also remember that the cost of the aquarium itself does not include the cost of care, maintenance and stocking. These items can easily tack on an extra $800 to $1500 per year.

Most internal filters will cost $50-$80, while an external filter can cost over $100. Heaters and lighting systems should be $40-$80 each.

You must also take the cost of the fish themselves into consideration. Some particularly exotic fish may cost over $50.

Certain habitats are more expensive to set up and maintain than others.

For example coral reefs and reptile paludariums are among the most expensive.

Consider a tropical freshwater aquarium if you are on a tight budget. It is one of the cheapest setups for a tank of this size and also well suited to beginner fishkeepers.

What to Consider When Buying This Tank

75 Gallon Aquarium Plants

Keeping a 75 gallon aquarium is as much of a commitment as keeping any other pet.

Fish are not disposable pets and many of them live for over a decade.

The first thing you will need to consider is the amount of space you have to dedicate to this tank. What size and shape will fit the best in your space? You will also need to consider what size aquarium your fish will need. What is their swimming distance? Do they gather in large schools or shoals?

Measure the dimensions of your chosen space before you purchase an aquarium, then pick the size and shape that will fit just right.

Once you have figured out the space, you will need to calculate your budget.

When selecting the equipment you need to pick the best equipment for your budget as well as for your habitat.

Certain aquascapes need special equipment that others may not.

All aquariums need a heater, filter, lighting system, cleaning equipment and water quality monitoring kit. Some fish and plants need an air pump to add extra oxygen to their water.

Higher quality equipment costs more, but it will last longer. If you opt for cheaper equipment then you will likely end up spending even more on constant replacements and repairs.

Also cheaper equipment tends to be noisier.

A very loud filter may disturb or distress fish that prefer quiet environments.

If you are running a tropical setup then you will also need a heater that can maintain temperatures above 72°F. The heater must be powerful enough to heat all of the water in your tank. A 300 to 400W heater for a tank of this size will be enough.

Also do not forget that many curious fish will attempt to leap up out of the tank, so a hood is a must.

Finally, you will need to consider their compatibility with one another.

When incompatible fish are kept together it can create problems. Certain fish may also be incompatible with the invertebrates in your tank or even plants. This will all need to be considered before you buy your tank.

75 Gallon Fish Tank Stocking Ideas

75 Gallon Aquarium With Goldfish

A 75 gallon aquarium can hold a huge variety of fish.

There are so many different species that can make your tank stand out.

Cichlids are some of the best freshwater fish to keep in a tank of this size. 75 gallons offers plenty of space for each Cichlid to establish their personal territory.

You can have a few Convict Cichlids, Jack Dempseys, freshwater Angelfish, and a pair of Oscars.

Goldfish thrive in a tank this size too. A single Goldfish needs at least a 50 gallon tank, but a group will be much happier in 75 gallons. This is enough space for you to keep the fancy varieties too, such as Fantails and Black Moors.

You can keep a group of up to 3 Giant Danios, as well as a pair of Clown Loaches. Small groups of Molly fish will add a pop of color to your habitat. You could also consider medium sized Plecos or Bristlenose Plecos.

75 gallons offers plenty of space for some of the most colorful marine fish too.

Butterflyfish, Wrasse and marine Angelfish are among the most popular.

You can even use a 75 gallon aquarium to host a single Lionfish.

Tank Setup Ideas

The Ultimate Goldfish Tank

A 75 gallon tank can hold many different kinds of Goldfish alongside some great tank mates.

You could start with 3 Veiltail Goldfish as the stars of your tank.

Their beautiful trailing fins will leave you captivated as you watch them swim.

Then you could add in a single Black Moor if you want a contrast to these lighter colored fish. If you want your Goldfish tank to look gold instead, you could include one Common or Comet Goldfish instead.

You can then add either a Bristlenose Pleco or Dojo Loach to add life to the bottom levels.

Finally, float duckweed on the surface of the tank so it resembles a natural fish pond. Tape grass, hornwort and watersprite will also provide a great natural look.

Tropical Technicolor Tank

This tropical setup focuses on some of the most colorful freshwater fish.

You can start with a pair of Giant Danios and a group of up to 4 Zebra Danios.

Then you can add in up to 2 groups of 5 Cherry Barbs – these vibrant little fish will make any aquarium stand out.

You can also include up to 3 Pearl Gouramis or a pair of Chocolate Gouramis.

Finally to add some life to the bottom of the tank, add in a group of 5 Emerald Cories. These peaceful bottom dwellers will not disturb your other tank inhabitants.

Amazon sword plants, Java moss and Java ferns make the perfect green backdrop for this tank of many colors.


A tank of this size can easily be used as a paludarium.

You can furnish the terrestrial areas of your tank with anubias, peacock moss, and plenty of logs.

Include up to 4 Apple Snails, and up to 3 small tree frogs.

The aquatic area should mimic a natural jungle pool. In the wild these would be full of Tetras, Rasboras and other nano fish.

A group of 6 Harlequins and a group of 8 Cardinal or Neon Tetras adds a burst of color to these murky depths. Include Amano Shrimp and Oto catfish to liven up your bottom levels.

How To Set Up A 75 Gallon Tank

Setting Up A 75 Gallon Tank

Most of your tank setup will be done long before you add any fish and plants to your aquarium.

After you unbox your aquarium you should clean and dust the inside and outside and set up the hood and stand.

Then you can assemble your heater, filter, lights and air pump.

Once your tank is set up, it is time to clean and layer your substrate. Rinse the substrate with a hose or under the faucet until the water comes out clean. If you have multiple grain sizes then the finest grains should be set down first. A 75 gallon tank will need about 55 pounds of substrate.

Next, it is time to fill your tank with water. If you are keeping a freshwater tank, the water must be dechlorinated. Water in a saltwater tank must be enriched with marine salts.

Check the salinity and pH once you fill your tank up, and adjust the water temperature until it is right for your environment.

Now it is time to cycle your tank.

Some of your hardier plants can be added before you cycle your tank, while the more delicate ones should be left out until cycling is complete. Tank cycling mimics the nitrogen cycle that occurs in every aquatic environment. Simply power on your tank’s equipment and leave it to cycle for 6 to 8 weeks.

You can add your fish once cycling is complete.

Each fish must be acclimated to your tank before you add them.

You can do this using the bag method

Float your fish in a bag on the surface of your tank and replace 25 percent of the water in the bag with water from your tank. Every 10 minutes, add one cup of water from your tank to the bag. Repeat this process for up to one hour.

Use a small net to gently place your fish into the tank.

Monitor their behavior carefully to make sure that it is fully acclimated. You must repeat this process for each new fish that you add to the tank.

Common Problems

Cleaning A 75 Gallon Aquarium

One of the biggest problems with a 75 gallon tank is overcrowding.

If you are moving up from a smaller tank then lots of people will overestimate the amount of space that is actually available in their tank.

A tank this size can hold a lot, but it cannot hold everything.

Many species of fish need even larger tanks or must group together in numbers that this tank cannot accommodate.

Even some smaller fish (such as Rainbow Sharks) need more than 75 gallons to avoid getting into conflicts with their tank mates. Do not automatically assume that a fish can fit just because of its size.

Overcrowding your aquarium will make your fish very unhappy and lower your water quality. Be aware of the space constraints for every fish that you plan to add.

Another common problem with a tank of this size is cleaning.

A diverse habitat generates a lot of waste – this dirt and grime goes a long way in a 75 gallon container. Dirty tanks can breed fatal bacterial infections.

Most of these issues are caused by inadequate filtration.

A filter that is too high or too low in power can create a problem.

This tank does not need an extremely powerful filter, but it must still be powerful enough to cycle 75 gallons of water on the regular. Make sure that you choose a filter that is right for your fish and your tank. Read the label carefully and pay attention to intensity, volume and flow.

You will also need to perform a 25 to 50 percent water change every 2 to 4 weeks to keep the tank clean.

Should You Get A 75 Gallon Aquarium (Summary)

If you want to take on a larger tank for the first time then the 75 gallon could be the tank for you.

It is recommended that you have a little bit of experience with smaller tanks before trying an aquarium of this size.

This tank is the perfect size and there are plenty of options here for fishkeepers on a budget. Most of the equipment that you will need for this habitat is very affordable.

Most of all, keeping a 75 gallon aquarium is fun.

It gives you the opportunity to be creative and resourceful while designing your own personalized aquatic environment.

In no time at all, it will become the showpiece of your home.

Which fish do you keep in your tank? Let us know in the comments below…