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Fish Tank 75 Gallon For Beginners

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Intro to 75 gallon tank

A 75 gallon tank is the ideal size for most aquarium lovers. It’s large enough to keep many fish and plants, but it doesn’t require too much equipment to manage. These aquariums are labeled as big fish tanks under general aquarium standards. Fish tank 75 gallon has just the right amount of space, so you don’t need a powerful filter or a high-end heater. And there’s plenty of space for a nice aquascape that makes it easy to stock with fish and plants.

Whether you’re new to keeping a tank or you’re an experienced aquarist looking for fresh ideas, the hobby of fishkeeping is filled with fascinating facts, innovative equipment, and a passionate community. Starting out the hobby with a 75-gallon tank is what we recommend at petfish101. Smaller and medium-sized fish tanks generally start from 2.5 gallons and range up to 40 gallons. They are comparably difficult for newbies to take care of. One of the main reasons is that the water in the smaller fish tanks tends to get spoiled rather quickly. And just like that, their precious fish can die overnight. Such incidents are devastating for beginners in the aquarium hobby and they often end up giving up. Therefore, 75 gallon comes as an ideal fish tank for beginners, as they are more prone to water quality changes than small aquariums. Moreover, these fish tanks do not require vigorous maintenance schedules like much bigger aquariums.

If you’re ready to learn more about freshwater and saltwater 75 gallon fish tanks, then this guide is an indispensable resource. So keep reading until the end!

Why a 75 gallon Tank?

A 75 Gallon fish tank as a centerpiece of your home

When you become mature in the fish-keeping hobby, you understand that the 75 gallon is much more than just a fish tank. You will accept that It has become the relaxation center of your home. Because a fish tank 75 gallon is just about the perfect size for most homes, it provides a beautiful centerpiece for any living room or a living area regardless of how larger or luxurious the place is. With enough space to comfortably house many plants and fish, you’ll enjoy having an oasis of relaxation right in your own home.

A 75-gallon tank is much larger than most of the standard aquariums sold at pet stores, but it will allow you to create a mini-ecosystem with beautiful plants and thriving fish. If your space doesn’t allow for a 75-gallon tank, you can always buy two or more smaller aquariums instead. They’re easier to set up and maintain, and they look great when arranged together. But they need extra care in terms of keeping good water chemistry. In short, they are delicate places for fish to be and might not be the best option for newbies.

75 galloons are ideal aquariums for those who are just starting out or those who are looking to try something a bit larger. This is why these aquariums are very famous in the hobby. They often make a great choice for anyone in the hobby regardless of their expertise.

Things to consider when buying a 75 Gallon Tank?

There are several factors that you have to consider when buying or making a fish tank 75 gallon by yourself. Let’s understand them one by one now.

1. Size and type of the fish

Fish size Vs Required Water Volume

This is the major factor for deciding any aquarium size. The size of your tank depends on the size of your fish. 75 gallons is a great home for larger fish like Goldfish and Cichlids. There are standard and widely accepted volume requirements for all the known freshwater fish species. These volumes are decided by the fish size, age, temperament, staying solitary or in schools, swimming speed, hardiness, the amount of oxygen required, and so on. For example, at least 30 gallons are required by a couple of fully-grown freshwater angelfish. And at least a minimum of 25 gallons is needed for an adult piranha fish.

Therefore, you must carefully plan what fish you are going to keep in your 75 gallons. And check for their fully-grown sizes to make sure that they fall under the size of the tank you wish to buy, which is a Fish Tank 75 Gallon in this case.

Another thing you want to beware of is that a 75-gallon tank is a great size to house fish that come from tropical climates. There is plenty of large fish that come from these climates that are ideal for large aquariums. You can also do some great mixing and matching of your fish. For example, you can have both your goldfish and your tropical fish in the same tank.

If the space your fish requires exceeds the size of the tank, you will find that you have to change the water more often. And with aggressive fish species, you will encounter a lot of issues such as domain overlapping, nipping fins, and at worst even eating each other.

One of the great options is to go for smaller fish like tetra or guppies as you may keep a big shoal of them in a larger tank like 75 gallons. You may create a great, natural-looking aqua cape with a bunch of these smaller fish with no serious issues. Swimming shoals of tetra, barb, or guppies can create such magnificent natural sceneries if you can plan wisely with your aquarium.

1.2 community fish aquariums

Community Fish Tank

If you like to set up a community tank, this is the perfect size for an interesting community environment.

A tank this size is large enough to house a dozen small, schooling fish without overcrowding them. Harlequin Rasboras, for example, have a group mentality and prefer living in large schools. Two small schools of them (maybe a dozen or fifteen fish or so) would get on well in a fish tank 75 gallon. You’d need to be careful with them and the Goldfish though. Harlequins are small but long and slender fish.

A dozen Guppies, Platies, and/or Swordtails would do well in a tank this size. As would a half-dozen Tetras, Rasboras, and/or Dwarf Gouramis. You could even house a group of Corydoras and other bottom-dwelling catfish in there.

Even though you can fit more fish in a bigger tank, you need to keep an eye out for compatibility issues. If you have a hard time keeping them together in a smaller tank, they won’t suddenly mix better in a bigger one.

A good rule of thumb is to look at how many fish you can have per gallon of water. As explained above section, checking the number of gallons in the tank will give you a good idea of how many you can put in it.

2. The physical space required to place a 75 gallon fish tank

The 75 gallon isn’t a small tank and it isn’t a medium-sized tank either. So no matter if you are going to build it by yourself or order it from somewhere, it’s always advised to have a good idea beforehand of how big these tanks can be.

A standard 75-gallon tank is typically 18 inches (or 45 centimeters / 1.5 foot) in height, 48 inches (roughly 120 centimeters / 4 feet) in length, and 21 inches (or 53 centimeters) in width. So, make sure that your living space will be able to accommodate the correct dimensions.

Moreover, when filled with water your fish tank can be as heavy as 385 KGs. So you have to be cautious about where you are going to keep the tank, especially if you are planning to keep it upstairs.

3. Maintenance & fish care

Fish Tank 75 Gallon Maintenance

A large aquarium is a beautiful thing to add to your home, and a great way to get animals into your life. However, larger tanks require more equipment and more frequent maintenance. So, before you go about choosing your fish tank size, think about the amount of time you’ll have for water changes, cleaning the glass, or dealing with fish-related issues such as illnesses.

There’s a saying in the aquarium field as follows, “Don’t buy a tank bigger than you have time for.”

3.1 Water changes

Any size of a fish tank does require regular water changes. The water changes required are different from tank to tank due to many factors such as the different fish they house. As a rule of thumb the difficulty of maintenance increases as the aquarium size increases. Therefore the amount of water needed to remove and refill in regular water changes increases with larger aquariums like 75 gallon tanks.

3.2 Larger and more expensive equipment

Larger aquariums require larger equipment. As with any aquarium you have to maintain the water temperature and cleanliness of the tank, you will also have to buy a hood that keeps excess heat out, filtration equipment, and other products to help maintain your tank’s water conditions.

3.3 Watch out for the temperature leaking

It is important to note that while you’ll have a lot more space to work with, the larger surface area of the water means a bigger tank will lose heat faster. You’ll need to make sure you keep a closer watch on the temperature, especially if you have a Goldfish in there that likes the water on the cooler side.

4. 75 gallons can be expensive!

Larger aquariums require more materials and equipment than smaller options. In addition to the price of a larger tank, you’ll also want to buy enough substrate, a heater, an air pump, and other necessities to keep your fish comfortable and long-living.

Read about how long do Angelfish live.

The price of a 75-gallon fish tank setup can range extremely. Depending on different setups and materials the price can range from a couple of hundreds of dollars to something like a whopping 5000$. Again, all these price tags depend on the factors like where you get your materials from, whether you buy brand new equipment or not, and the nature of the aquarium you want to set up.

Moreover, you must be willing to spend couple more hundred dollars annually for maintaining a big tank like a 75 gallon.

75 gallon Tanks Vs Beginners

As we mentioned before we recommend buying a fish tank 75 gallon if you are a beginner, or if you have kept fish before and are looking to try something that’s a bit bigger. You can choose among many different finishes and add-ons, down to the lighting and the stand.

If you aren’t a fish expert, or you just want to keep some of the best aquarium fish, then a 75-gallon tank is your best bet. With enough room and not too much equipment, this is a great size for any hobbyist that doesn’t have experience or time to care for larger aquariums.

Moreover, 75 gallon is a perfect size, not so small or not so big. The water quality is smaller tanks are harder to maintain as they can be spoiled overnight. Nitrogen spikes can kill fish if you are just beginning with smaller tanks with more fish. On the other hand, bigger tanks can be difficult to maintain as well. From scaping to water changes a lot of things can be overwhelming to the newbies. So, better go with the perfect middle-sized 75 gallon fish tanks.

However, the first tank you buy may not be the one you have for the rest of your life. If you decide that a larger tank is more suitable for you, then you will be on your way to owning a whole new set of aquarium supplies.

75 gallon freshwater fish tanks

Keeping a freshwater 75-gallon fish tank is much easier than keeping 75-gallon reef tank. Ready-made 75 gallon aquariums are perfect for beginners. It’s a good fit for small living rooms, and the size makes it easy to maintain and affordable. They come with smart lighting, a top-of-the-line filter system, and energy-efficient heating units. Everything you need to set up a healthy ecosystem for your fish.

If you are going to keep tropical freshwater fish, then you’ll need a heater to maintain temperatures between 75–80ºF. Choose a minimum of 225-watt heater for a tank of this size. A good rule of thumb is to follow the manufacturer’s specifications on how powerful a heater that you need.

75 gallon saltwater tanks

75 gallon saltwater tanks

Saltwater tanks are not for everyone as they require special care and maintenance. There are many things that can go wrong in a saltwater tank when compared with a freshwater fish tank. Hence we suggest you first keep a freshwater tank and then move on to much more complicated reef aquariums. The water parameters including the salinity should always sit in the correct range, or else you are risking the life of your fish. When you have live corals, sea anemones, and saltwater invertebrates you can’t use many of the medications out there to treat possible fish diseases like saltwater ich. This is why you should prevent any diseases in the first place. Crystal clear water, correct lighting, and the right temperature are mandatory for Corel growth.

But the good news is that a fish tank 75 gallon is a perfect balance between providing enough space and not requiring lots of maintenance. A tank this size will keep most saltwater fish alive and healthy, as well as a wide variety of anemones, soft corals, and other invertebrates. Because it requires less equipment to run than a larger tank, it’s also easier to maintain. Though more powerful filters and heaters are required, they aren’t especially difficult to manage.

Setting Up a 75 Gallon Tank

You have to do some research before going ahead with your 75 gallon fish tank setup, as different fish have unique needs. You will have to consider whether you are going to do a fresh or saltwater tank, whether you will use an aquarium air pump or not, or how you can keep your water in ideal conditions, and how you should clean your tank.

Things you need for a fish tank 75 gallon

An aquarium Hood

Whether your 75 gallon requires a hood or not vastly depends on the type of fish you keep. If you are going to house fish like snakeheads or Arowana then you definitely need a hood. A hood can be made of glass, or it can be even plastic or wood. If you are using a wooden hood, then give extra focus to keep it dry all the time. And you must apply a wood-protecting coating.

Remember that the hood needs to facilitate your aquarium lighting as well.

Aquarium lights

If you are going to buy a ready-made 75 gallon fish tank, then there should be an aquarium light as part of the package.

Or you can just buy the light separately from your local fish store. Try to go for LED aquarium lights as they are more durable and provide the best quality lighting.

If you are planning to keep aquarium plants, then you should buy an LED light suitable for plant growth. Usually, these contain blue LED lights along with white ones. Some even have green lights as well.

Check out these recommended LED lights for your freshwater 75 gallons planted tank.

If you are planning a reef tank, then you must buy powerful lighting which can provide 14,000K on average. Check out below recommended LED lights for 75 gallon reef aquariums.

Aquarium stand

It’s a very bad idea to keep your aquarium on the floor. To have the greatest interaction and enjoyment, you must be able to watch the aquarium at your chest level. Ready-made stands are available to buy from your local fish stores. Or you can just make a steel stand protected by an applied corrosive protector.

Aquarium filter

You can use any aquarium filter if it’s adequate for cleaning a 75 gallon properly. These can be mechanical filters, bio-filters, canister filters, or sump filters.

Generally, the flow rate should be between 240 and 450 gallons per hour (note that this can vary among freshwater and saltwater tanks or planted or non-planted tanks) for a fish tank of 75 gallon. Go for the higher range if you have heavy biomass or messy eaters in your aquarium.

Air pump

The filtering mechanism can mostly provide the required oxygen for your tank. But if you find any signs of low oxygen levels you should definitely buy a separate aerator.


If you are going to keep fish whose natural habitat is fast-flowing waters, then consider buying wavemakers. Usually, reef tanks require wavemakers as the coral-dwelling fish are used to living in fast-moving currents.


You either need a heater or a cooler for your 75 gallon fish tank. These aquariums are big, hence can leak or absorb heat rather quicker than smaller fish tanks. Fish are cold-blooded creatures also known as ectothermic or poikilothermic, so they can’t regulate their body temperature. This is why you need equipment to maintain water temperature depending on which kind of fish you are housing.

 You need a 225-watt heater at a minimum for a Fish Tank 75 Gallon.


A thermometer is very handy for measuring water temperature.

Water testing kit

A water testing kit is essential for any kind of aquarium. So you can keep track of the water parameters for any signs of ammonia spikes or PH changes.


Substrate choice for your tank depends on which fish and plant you are going to have. If you have bottom-dwelling fish that always look for food in the bottom of your tank, a sandy substrate is ideal. If you are going to have plants then you should buy a soil substrate as well.

Setting up the fish tank 75 gallon

Now that we have everything we need to build our Fish Tank 75 Gallon.

Prepare the floor & Place your stand and aquarium

You have already chosen the place for your dream aquarium. Now it’s time to place the aquarium stand in place and then place the actual aquarium on top of the stand.

The most important thing during this step is to level the aquarium. If your floor isn’t leveled then you must level it as you place your aquarium. You can use thing metal sheets or something suitable (which can withstand the weight of the filled aquarium) to level your fish tank. If the floor isn’t leveled, chances are that you are going to break your fish tank in the future while there are fish in it!


When you place your aquarium on the stand, make sure to place a rigid form at least 0.5 inches thick. This helps absorb all the weight and pressure coming from your aquarium’s glass bottom and safely deliver it to the stand.

Rinse what must be rinsed

75 gallon aquarium setup

You have bought soil, sand, decorations, driftwood. All these can carry unwanted substances which can mess up water quality in your tank. So you need to rinse them and clean them. If you are using driftwood, then those must be properly sterilized before use.

Check all your electrical devices and cords

Safety first! You must check all your wire cords, heaters, air pumps, etc for possible damages before using them in the actual setup.

Setup your filter, air pumps, wavemakers, and heaters

Now you can place set up all the electrical devices. But don’t plug them yet! There’s a lot more to do before that. Remember safety first!

Place your substrate

Now place your sand soil or other substrates on the bottom of the tank.


Don’t directly put any heavy rocks, driftwood, or material with sharp edges on your 75 gallon tank’s glass bottom, as it may shatter the glass sooner or later!

After carefully placing a substrate layer on the bottom of the tank, now you can put heavier ornaments, rocks, and driftwood on top of it. Give extreme care to place a thick layer of the substrate before placing any heavy rocks on top of it.

Create your stunning aquascape

Now you can start creating your aquascape. You can use driftwood, and rocks for creating the hardscape. Then start planting live plants and complete the setup.

Remember to use your skills in aquascaping to hide any electrical devices like filters and pumps from the front view.

FIll in the water

Now you can start filling the water. You must take necessary precautions to let the water flow into the tank smoothly without messing up your delicate aquascape and live plants. You can use a bucket or a polyethylene cover to achieve this goal. While filling the tank look for any leakages. Stop filling water if you discover any.


You must treat your aquarium water beforehand if you are using tap water mixed with chlorine or chloramine.

Let the fish tank 75 gallon cycle itself

After filling the water don’t just add your fish in it. It’s a really bad habit with serious consequences. New aquariums can’t handle ammonia in the water. As only good bacteria can break down ammonia from the water so they can be used by plants or become harmless to fish. It takes some time for good bacteria to establish their colonies in your filter and under the substrate. Usually, this can take as long as 6 to 8 weeks. Test the water until you see zero ammonia, and 0 and 0.2 ppm (ml/g) nitrites reading.

you can kick start cycling by introducing 1 or 2 hardy fish while you cycle the tank. Or using filter medium of an already cycled tank. (note that this tank should be free from any fish diseases.)

We know that aquarium hobbyists don’t want to wait for a long time, so can we cut down the cycling time?

Quick tank cycling tip

The best way to add your fish into your new tank without waiting is to use old filter media from an already cycled tank. This tank should be free of fish diseases as you don’t want your new fish to get sick.

By adding such filter media with an already established colony of beneficial bacteria, you can add your fish in 24 hours without waiting for a long time. But you must test your water for any ammonia or nitrites before adding your fish. And keep checking the water frequently, because the bacteria added might not be enough. Until the tank establishes its own beneficial bacteria colonies everywhere possible, you must regularly check water and do water changes. Also, don’t forget to feed your fish only the amount they need and clean any leftovers. And don’t overstock your fish tank with fish!

Adding fish

Finally, you can add fish to your Fish Tank 75 Gallon. Test the water before doing so.


Don’t just release the fish into the new tank. You must acclimate fish before adding them to your aquarium. You can do this by keeping them in their bag or container floating in the aquarium until their water temperature balances with the aquarium water.

Benefits Of 75 Gallon Fish Tanks

freshwater 75 gallon tank

Beginners and people with limited space should look for a tank that holds at least 20 gallons of water to see their first fish. Tanks of this size are easy to maintain and ensure small, hardy fish like zebra danios or cherry barbs live comfortably. The 75-gallon tank is the sweet spot between having enough space to keep your favorite fish and not becoming a full-time hobbyist by needing advanced gear to maintain it.

But the problem with smaller fish tanks is that despite how easy they seem to maintain as they hold a lower amount of water volumes, they need constant and special care to keep stable water parameters. The hardness, PH range, and ammonia levels can go wrong very quickly in smaller tanks. When the water goes bad, fish diseases follow. And these fish diseases can spread rather quickly in smaller fish tanks as the healthy fish has no room to stay away from sick ones

So, we recommend larger fish tanks like 75 gallons for successful fish keeping, especially for beginners. These tanks require larger amounts of water changes which many of us are very much capable of handling!

Larger tanks have more room for keeping big fish or shoals of fish. But the smaller tanks can handle a few fish and smaller fish like betta, neon tetra, or cherry barb.

Fish Tank 75 Gallon is ideal for creating natural aquascapes. There’s a lot of room for experimenting with different aquascapes as you wish.

Unlike very large aquariums, 75-gallon tanks can be made by the hobbyist. This can be very useful to reduce costs.

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