75 Gallon Tank: 22 Things You Should Know (For Beginners)

A 75-gallon tank is one of the best choices to choose from when purchasing aquariums or terrariums for your fish, reptile, amphibian, plants, etc.

A big 75-gallon tank would give plenty of benefits to a pet owner who’s interested in expanding their collection of pets and plants.

So what exactly can you stuff inside a massive 75-gallon tank? What are your options in terms of stocking?

How Many Fish Can I Put In A 75 Gallon Tank?

One inch of fish per gallon is the general rule, however, this doesn’t give accurate results all the time. Fish vary in size, shape, and swimming space, so applying this rule to every fish you’ll own will result in catastrophic proportions.

This doesn’t just apply to 75-gallon tanks; this applies to every tank size there is. You can’t deny that there’s a ton of fish available in the market and they have drastic differences from one another.

To make things easier for you, we will be listing the factors you have to consider when choosing a fish to put inside a 75-gallon tank. Ultimately, you will know exactly how much fish you can put in a 75-gallon tank.

Factors That Would Determine The Number Of Fish In A 75-Gallon Tank

  • Temperament (aggressive, predator, or peaceful)
  • Species of fish
  • Territory requirements (water requirements/tank size)
  • Size of fully grown fish based on its species

The temperament of a fish is included here because that would largely affect how many fish can live in a tank. For example, an aggressive fish like the Convict Cichlid can’t have a female Convict Cichlid tank mate as it will result in territorial behavior and aggression.

Moreover, there are only specific tank mates that are compatible with the Convict Cichlid such as Pictus Catfish, Oscars, Silver Dollar Fish, Jack Dempsey, and Clown Loach.

What Fish Can Live Inside A  75-Gallon Tank?

A 75-gallon tank, thankfully, is a tank that is big enough to house several kinds of fish. We will be providing a list of some fish that can be kept in 75-gallon tanks and how many of them you can keep inside these tanks.

These are only to name a few fish that can live in 75-gallon tanks. There’s much more variety of fish that people can choose from if they own a 75-gallon tank.

Also, some of these fish are classified as centerpiece fish and what that means is that they are the spotlight of the tank. Tankmates would be the additional bunch and the number and type of tank mates would depend on what your centerpiece fish would be.

Is A 75 Gallon Tank Big Enough For 2 Bearded Dragons?

A 75-gallon is too small for two Bearded Dragons. A 75-gallon tank can only house one Bearded Dragon since these reptiles don’t need companions and keeping more than one inside a tank isn’t recommended.

A Bearded Dragon grows from 18 to 22 inches and this type of size can only be accommodated by 75-gallon tanks and above.

Bearded Dragons are known for being territorial and this is why they don’t require any companionship as it would only do more harm than good.

Is A 75 Gallon Tank Too Big For A Leopard Gecko?

A 75-gallon tank is not too big for a Leopard Gecko since the bigger the tank is, the more space there would be for the gecko and hiding spots like branches and rocks (for climbing).

Leopard Geckos grow fast, and when they do reach adulthood, they will end up measuring up to six inches or more. Getting a 75-gallon tank on the get-go is better than buying a small tank since juvenile Leopard Geckos grow quickly.

On a side note, the minimum tank size for a Leopard Gecko is 20 gallons, however, your best bet would be a 75-gallon tank. The bigger the tank is the better since this makes up more space for decorations, hides, water bowls, and food bowls.

Is A 75 Gallon Tank Good For A Hamster?

Ideally, a 75-gallon tank is good for hamsters since this could make room for a hamster’s necessities and provide more floor space overall.

75-gallon tanks can house several types of hamsters, however, it’s the owner’s responsibility to know whether or not the species of hamster they have is comfortable with having a companion.

Some hamsters prefer to live alone since they have territorial behaviors. Also, trouble will ensue if they’re kept with another hamster, the worst-case scenario would be resulting in the death of a hamster.

Hamsters that should live alone are Syrian/Golden Hamsters and Chinese Hamsters.

Is A 75 Gallon Tank Big Enough For A Yellow Tang?

No, a 75-gallon tank falls below the minimum tank size for a Yellow Tang, which is 100 gallons mind you. 75-gallon tanks would be too small for Yellow Tangs.

Yellow Tangs are saltwater fish that grow up to eight inches which are considered big already. If the fish is receiving great care from its owners, then expect it to grow one to two inches per year.

Furthermore, a Yellow Tang fish needs a lot of swimming space, to provide this for these fishes, they must have a long tank. The perfect tank size for them would be 150 to 200-gallon tanks.

Refrain from getting a Yellow Tang fish if they would only end up being kept in small tanks that are less than 100 gallons. This would only make them stressed and increase the chances of getting diseases.

Can An Arowana Live In A 75 Gallon Tank?

No, an Arowana can’t live in a 75-gallon tank because this is too small for them. The ideal tank size for Arowanas would be 125 to 250 gallons, the latter being the best choice.

Arowanas are far from being small fish, they’re massive in size as they can reach up to three feet. So you can only imagine how restricting a 75-gallon would be for a large fish like the Arowana.

If you happen to purchase a juvenile Arowana, which is two to seven inches long, it’s best to have a 240-gallon tank ready so that you won’t have to spend more than twice on tanks in the long run.

Arowanas are semi-aggressive fish so you should be mindful of what type of fish their tank mates would be. Here’s a list of compatible tank mates for Arowanas:

  • Silver Dollars
  • Clown Loach
  • Black Ghost Knifefish
  • Pacu
  • Green Terror Cichlid
  • Plecos
  • Dinosaur Bichir
  • Peacock Bass
  • Black Banded Leporinus
  • Datnoids
  • Parrot Cichlid

What Tangs Can Live In A 75 Gallon Tank?

There are no species of Tangs that can live in a 75-gallon tank because they require a much bigger tank to accommodate their large swimming space.

Take note, the various species of Tang come in all sizes, most, if not all, are large fish such as the Naso Tang (18 inches), Clown Tang (14 inches), Black Tang (10 inches), Sailfin Tang (15 inches), and so on.

So the only viable tank size for Tangs would be a minimum of 100 to 150 gallons, if you can go higher than that, the better. Just remember that Tangs are saltwater fish that swim for miles in the wild, so they need at least six feet of swimming space to not be stressed and aggressive.

How Many Yellow & Blue Tangs Can Live In A 75 Gallon Tank?

None. A 75-gallon tank would only make a Yellow and Blue Tank stressed and aggressive because they’re not getting enough space to swim in (they need at least six feet of swimming space).

With that being said, if a Yellow and Blue Tang are kept in a fairly large tank, a minimum of 100 to 150 gallons, then they must not live alongside other Tangs since this would result in fights that would lead to injuries later on.

Tangs can live peacefully amongst other species of fish (must be saltwater fish) such as:

  • Clownfish
  • Cardinals
  • Large Angels
  • Wrasses
  • Chromis

How Many Mollies Can I Put In A 75 Gallon Tank?

The number of Mollies in a 75-gallon tank would depend on their species. Sixteen Mollies (the small ones) can be put inside a 75-gallon tank.

As for large Mollies, like the Sailfin, they would need 30 gallons and an additional five gallons per additional fish.

A single Molly would need a 10-gallon tank, so for a larger tank, let’s say a 40-gallon tank, it would be able to house up to four Mollies. If you would like to add more fish, be ready to allot an additional five gallons per fish.

With that being said, here are a few rules to take note of when keeping Mollies inside a 74-gallon tank:

  • The ratio of Mollies inside the tank should be two to three females per one male Molly (if there are more males than females inside the tank, aggression will most likely occur).
  • Mollies can live alone, however, it’s best to keep them in groups of four and above. If you have plans on keeping only a pair of Mollies, it’s best to get two females.
  • If you will only keep a pair of Mollies, don’t keep a male and female in the same tank as that may cause stress to the female and kill her eventually.

How Many Leopard Geckos Can I Put In A 75 Gallon Tank?

You can only have one Leopard Gecko in a 75-gallon tank because they’re animals that don’t need companions and are solitary animals by nature. Keeping more than one Leopard Gecko inside the same tank will cause territorial aggression.

Moreover, Leopard Geckos shouldn’t share a single tank no matter what gender they are as well. Keeping two males, two females, or a male and female Leopard Gecko together will only result in stress and aggression from both parties.

It’s also a bad idea to keep a baby Leopard Gecko with an adult Leopard Gecko since there’s a tendency for the adult gecko to bully the defenseless baby gecko.

How Many Angelfish Can You Have In A 75 Gallon Tank?

You can have five Angelfish in a 75-gallon tank.

If you wish to have more Angelfish in your 75-gallon tank, then you would need to buy a bigger tank. Always remember that the general rule for these fish is an additional 10 gallons per Angelfish.

Due to the size of the Angelfish, especially their fins, they will require a large tank that’s taller than long. This is to accommodate their fin size which is laterally long.

Also, a 75-gallon tank would be enough to raise a small school of Angelfish. However, there would be problems that could arise when keeping more than one Angelfish in the same tank, this would result in aggression, moreso during pairing and spawning.

Nevertheless, Angelfish are pretty peaceful themselves and are less aggressive compared to other cichlids. Also, Angelfish are occasionally territorial (during breeding time), to avoid this, just don’t overcrowd a bunch of Angelfish in a single tank and you’re good to go.

How Many Discus Can I Put In A 75 Gallon Tank?

You can have seven Discus in a 75-gallon tank. If you want to add more, it would be an additional 10 gallons per Discus fish.

Discus is a schooling type of fish, so they would thrive in a 75-gallon tank with their fellow species tank mates rather than living alone. They are also quite large, they measure six to eight inches, in some cases, they can even reach up to 10 inches.

Discus fish are relatively peaceful fish and can get along well with other species of fish, so long as they are tank mates who are also peaceful. However, you should watch out when they start to breed because they tend to become aggressive with each other.

Moving forward, you should avoid having these tank mates for your Discus fish so that they won’t be stressed and feel disturbed.

  • Angelfish
  • Clown Loach

The temperament and tank space that both of these fish need isn’t compatible with the Discus fish.

Nothing good would come from keeping either of these fish as tank mates for your Discus as it will most likely result in territorial behavior, aggression, and stress (stressed Discus fish will have a weakened immune system and will contract diseases easily).

How Many Jack Dempseys Can Live In A 75 Gallon Tank?

Only one Jack Dempsey can live in a 75-gallon tank because they’re big fish (10-12 inches) and would need a lot of tank space. If you would like to keep a pair of Jack Dempseys, then a 100-gallon tank would be the ideal tank size.

Another thing, Jack Dempseys are aggressive fishes, so this doesn’t make them an ideal candidate for a community tank. Under no circumstances should you keep two male Jack Dempseys inside the same tank because they will only end up hurting and killing each other.

If you still have plans on putting tank mates with your Jack Dempsey, then it would be better to get something larger than a 75-gallon tank. Don’t choose small fish since Jack Dempseys will only see them as snacks.

How Many Peacock Cichlids Can I Put In A 75 Gallon Tank?

You can only put one Peacock Cichlid inside a 75-gallon tank since these fish are active and will require a lot of tank space to swim around in.

A 75-gallon tank can only support one Peacock Cichlid because an additional Peacock Cichlid would require another half of the minimum tank size for these fishes (55 gallons is the minimum tank size).

With that being said, a pair of Peacock Cichlids would need about 110 gallons. So unless you’re willing to upgrade to a much larger tank, it’s best to stick with one Peacock Cichlid in a 75-gallon tank.

Moreover, male Peacock Cichlids can’t have a male companion of the same species. This would only spark aggression between the two due to territorial behavior. Also, males will show aggression towards females and other tank mates.

On the other hand, female Peacock Cichlids are compatible with their fellow females (of the same species).

Can My Floor Support A 75 Gallon Aquarium?

This would entirely depend on what type of floor you have. If you have a wooden floor, then chances are, a 75-gallon aquarium would cause creeping in your floor. Creep in wood refers to wood adjusting to an object’s sustained weight.

A 75-gallon tank is by no means a lightweight object. If you have wooden floors and have plans on getting a 75-gallon tank, then you might have to reconsider.

An empty 75-gallon tank weighs approximately 140 pounds while a filled tank would weigh around 850 pounds.

If you don’t want any permanent deflections on your wooden floors, then it might be best to go for a smaller tank. The only downside to a smaller tank would be the limited stocking options you’ll have to accept.

As for concrete floors, 75-gallon tanks will cause little to no changes on the floor. 75-gallon tanks would be best for floors that provide stability and firmness.

How Much Floor Space Does A 75 Gallon Tank Have?

The dimensions of a 75-gallon tank are 48 x 18 x 21. The floor space of the 75-gallon tank would equate to its dimensions.

Apart from floor space, owners must be wary when it comes to providing enough space for the tank in terms of the space between the tank and the wall and enough room for the back part of the tank to make cleaning more efficient.

Can You Put A 75 Gallon Tank On A Second Floor?

You can put a 75-gallon tank on a second floor, just make sure that the structure of your house can support it. Also, make sure that your floors are in great condition, meaning there are no holes and whatnot.

Moreover, it’s not recommended for homes with wooden floors to keep something as heavy as a 75-gallon tank. This would cause some permanent deflections on the floor, so it’s best to not get a 75-gallon tank for this kind of home.

Also, to make the 75-gallon tank more secure, it’s advised for owners to have a stand that could support the overall weight of the tank.

The average weight that second floors can handle is 300 pounds. Take note that floors can collapse if there is too much weight on them.

How Often Should I Change The Water In My 75 Gallon Tank?

This would depend on how much nitrates or bio-load is being produced by the fishes you’re keeping. The more fish you have, the more food is being consumed, and the more waste is being released inside the tank. This would result in frequent water changes, possibly once every week.

Water change schedules will always vary since not every owner owns the same set of fish. With that being said, owners must observe the nitrate levels in their tanks and base their water change schedule off of that.

The nitrate level inside a tank must always be below 40ppm, once it exceeds that, then it’s time to change the water inside the tank.

If you don’t want to clean your tanks as often as once every week, then it’s best to own less fish so that there would be less waste being produced.

Are Aqueon 75 Gallon Tanks Made Out Of Tempered Material?

Most Aqueon 75-gallon tanks are made out of tempered material, but only for the bottom of the tank and nothing else.

Tempered glass tanks provide tons of benefits so this is a solid choice for owners. Some benefits would include:

  • The ability to withstand the weight of heavy gallons of water.
  • The base of a tempered glass tank would be able to hold the weight of substrates and rocks.

It’s no wonder tempered material tanks are being favored in the fish community since these truly offer sturdiness and stability.

Can I Drill A 75 Gallon Tank?

Yes, you can drill a 75-gallon tank, but only if it’s made out of non-tempered material.

Tempered glass material can’t be drilled, so that makes non-tampered material completely safe to drill, but only by qualified technicians.

If you want to drill your 75-gallon tank but you’re unsure of what type of material it’s made out of, then we recommend you not to drill it at all. This would most likely cause damages to your tank, especially if it ends up being made out of tampered material after all.

Aqueon Standard Glass Aquarium Tank, Repti Zoo Large Reptile Terrarium, and Aquatic Fundamentals would be the most popular 75-gallon tanks.

We’ve included one terrarium for the popular 75-gallon tanks since there are owners who are interested in purchasing this particular tank size for their non-fish pets such as amphibians, reptiles, and small mammals (hamsters).

You may check the links below to find out more about these high-rated and quality tanks:




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