125-Gallon Fish Tank (Everything You Need To Know)

You can comfortably keep 50 fish in a 125-gallon fish tank. When it comes to fish, it’s not always true that a giant aquarium is better for your pets.

Maintaining and caring for your pets will be much easier if you have the right tank size.

Please keep reading to find out how much maintenance a large tank requires, how many fish it can hold, and whether or not it’s worth it to have such a massive tank in your home in the first place!

How big is a 125-gallon fish tank?

Standard Size: 72″ x 18″ x 21″

A average 125-gallon aquarium has a capacity of 568.261 Liter a 125-gallon fish tank is around 8 feet in length and 2 feet in breadth.

This tank can accommodate adult-sized aquariums since it has a volume of 23 cubic meters for adult-sized balloons.

As an example, a typical goldfish bowl has a volume of approximately five cubic meters.

Customers may choose from a variety of aquarium sizes at almost any pet shop or online vendor that offers aquariums.

Cost of 125 Gallon Fish Tank

Typically, a 125-gallon tank costs $1,000. The kind and size of aquarium you choose will determine its cost.

Tanks range in size from 150 gallons to 500 gallons, depending on your specific needs.

They are often made of acrylic or glass, but there are also metal options on the market.

Despite being lighter than glass, acrylic tanks scratch more easily and will need replacement sooner rather than later owing to usage.

A custom-built design with features like LED lights or waterfalls can cost anywhere from $5,000 to $10,000, depending on what you’re looking for.

Fish selection for 125-gallon tank

In general, an aquarium of this size holds about 125 gallons of water. But some are significantly larger or smaller than this.

The kind of fish you wish to maintain and the quantity of fish you intend to house at any one moment will decide the size of your aquarium.

For example, if you wanted to keep ten guppies in your aquarium, you would need at least 20 gallons.

However, if you had two trout in a 10-gallon tank (2×5=10), they would be fine.

All aquarium owners must be aware of these calculations because it helps them determine how much money and space they may need for their fish tank.

Which fish can be kept in a 125-gallon tank?

Everything will depend on the kind of fish involved.Larger fish require a tank with a minimum volume of 400 gallons or more.

These include Kuhli loaches and Otosinseturichyotes Elongates, Angels (Pterophyllum Scalare), Corydoras sterbai, and a few other species.

Parachromis managuensis and angelfish like Pterophyllum leopoldi or severums can be kept in 125-gallon tanks, like other cichlids, such as the angelfish.

There are saltwater varieties that can also be saved, but they aren’t always readily available in pet supply shops.

How much does a 125-gallon aquarium weigh?

The weight of a 125-gallon aquarium is approximately 1400 pounds. It may be necessary to borrow a truck or a trailer because pickup trucks can only hold about 2500 pounds, and probably not more.

How to purify water?

Replace half of the water in the tank with new, dechlorinated tap water once every two to three days. Also, drain and replace the remaining 50% of the water.

Start with the seafood. The best place to store your fish is in a cooler full of water rather than the aquarium or filter collector.

Remove any bio balls, rocks, plants, etc., from the filtration system.

Rinse off any food that has accumulated on the surface of the water. It is necessary to remove any algae or debris from the tank’s sides or floor before treating the water to prevent the growth of pathogens.

Pump activated carbon through your filters for 10 minutes, then turn on your pump for another 10 minutes to circulate the carbon through the system and remove any remaining debris.

As a result, you’ll have very little waste to draw from both sides of the filter.

You can use an algae magnet (like a cucumber peeler) or a scrubber pad to remove algae from your fish tank’s glass and hard surfaces; be sure to rinse thoroughly afterward to avoid recontamination.

Maintaining a steady flow of water through the day and night is the best way to prevent further sludge buildup in your tank.

A pump and an under gravel filter can be installed to improve circulation if that isn’t already the case.

Why it’s essential to change your filter and scrub your gravel regularly?

There will be a rapid decrease in water quality when you do not change your filter and clean your stone.

High nitrate levels can be deadly to your fish or plants due to the buildup of waste products in your aquarium.

A higher concentration in the aquarium leads to a greater variety of bacteria.

You don’t want to get your hands on “Hammerhead Wonders” when you’re cleaning metal pipes with a metal cleaner because these bacteria produce toxins and oxygen radicals that strip the linings of metal pipes.

Tips for keeping the aquarium plants healthy:

  • Keep the plants out of the direct rays of the sun.
  • Plants that require a lot of light should be placed in one area of the home or office and should not be placed too close to windows or outside lights, as this can cause them to dry out.
  • Trimming plant leaves and algae removal from glass, metals, and plastics should be done with soft bristles.
  • Among these is the loofah, a type of sponge with a rough face cloth attached.
  • Loofahs can harm delicate water plants by scraping away at their surface cells, making them more vulnerable to infection and death.
  • Aquarium decorations like shells do not usually harm water plants, but porous materials like wool or jute can.

How often should you feed your fish?

Every day. More frequently if the tank is filled with live plants that require regular fertilization.

At least two times a day, fish should be fed.Aside from their health, the color of your fish is a good indicator of how well they’ve been fed and cared.

Keeping an eye on your fish’s color and not providing them excessively are the main points of the rule.

What kind of food is best for your fish?

To feed your tank, you can add vegetables like cucumber, zucchini, and endive; if you want to grow plants, you can use plant fertilizer or kelp powder.

You also need to consider the size of their stomachs; a goldfish only requires one piece at a time, while an angel may eat six slices of cucumber at once!

The benefit of a 125-gallon fish tank over small tanks

  • 125-gallon tanks have more room for fish to swim and more surface area for bacteria to grow, making them ideal for larger aquariums.
  • Their smaller size requires fewer water changes than smaller tanks, making them more convenient to keep clean.
  • Since there is so much water in a 125-gallon container, ammonia production will be much lower than in a smaller tank.
  • Lower power bills can be achieved by using larger tanks rather than smaller tanks.
  • A 125-gallon tank is significantly less expensive per liter than a small aquarium or bowl, which can cost upwards of $500 or more.
  • Look for specific fish species in a large selection of fish at your local pet store rather than just one tiny bowl at the pet store.
  • These tanks are more sturdy and breakage-resistant than smaller tanks.
  • Larger fish can be kept in 125-gallon aquariums, as well as a broader range of species.
  • A 125-gallon aquarium has a more finished appearance than a 50-gallon tank, which gives the impression that it is an integral part of the space rather than an afterthought.
  • In addition, you’ll save money on electricity because there is less heat buildup from lights and filters running all day long in a much larger tank.

How To Setup A 125 Gallon Tank?

Putting together a 125-gallon tank is not a simple undertaking. You’ll need to be aware of the kind of fish you want, the maximum number of fish that can fit in the tank, and the size of the filter you want.

As a beginner, here are a few steps to get you started:

  • Decide on the type of aquarium you’d like to have.
  • The two basic types of tanks are freshwater and saltwater tanks.
  • Saltwater tanks are more difficult to set up and maintain, thus beginners choose freshwater aquariums.
  • Make sure you have all the equipment you’ll need, such as filters, heaters, and lights, for your aquarium installations.
  • Species choice – To get the most out of your fish tank, you should do some research into which fish would be best suited for the space you have available before making your final decision.
  • New tanks demand more care, so plan to devote more time to them.
  • Your tank needs to be thoroughly cleaned on the inside and outside.
  • Do this for an hour so that you can be sure that the tank is leak proof.
  • You must first place your tank in the correct area before you can level it.
  • You may either fill it with a half-inch or so of water, or use a spirit level.
  • The tank stand you’re using must be solid and sturdy enough for your tank.
  • Prepare your substrate and add the water now.
  • Fish tanks of this size require 125 to 250 pounds of substrate.
  • Substrates will need to be rinsed before it is added to the aquarium tank.
  • Depending on the sort of tank you have, the technique of adding water will differ.
  • When putting in an internal filter, make sure you put all of the pieces together.
  • You can now choose between a heavily planted tank or one with just a few plants and rocks.
  • Congratulations, you’ve finished setting up your tank! Despite its appearance, you will need to be patient and wait until the tank is cycled before you can add any fish.
  • It’s essential for the health of the fish you’ll be keeping in the tank down the road to cycle the water in your biological filter regularly.
  • Finally, add the fish of your choice and complete the setting.

How Big Should The Heater Be For A 125 Gallon Fish Tank?

The size of the heater for a 125-gallon fish tank depends on the kind of fish and desired temperature.

A heater rated at 100 watts or more is required if you want to keep the water temperature at 75-78 degrees Fahrenheit,

for example if you’re going to keep it at 78 degrees, you’ll need about 50 watts per 10 gallons of water.

Consult with an aquarist from your local pet store or a knowledgeable friend in the industry to determine what size heater is best for your tank’s heating requirements.

How to Care for a Fish Tank That is 125 Gallons?

  • Feed the fish three times daily to maintain their health.
  • Changing 10% of the water every week is a good practice.
  • Leaves and other plant life that have fallen into the tank need to be removed from the tank’s surrounding area as well.
  • Sprinkle some salt into the water to keep it clear and nutritious for your fish.
  • If they don’t finish the food you give them, take away what’s left, so there’s room for more food the next time you feed them!
  • If old filters need to be replaced, swap them out for new ones.

What temperature should the water in my fish tank be?

Tropical fish prefer a temperature range of 22-27 Celsius, while cold-water fish prefer a temperature of less than 22 Celsius.

How Big Is A 125 Gallon Fish Tank?

A 125 gallon fish tank is a pretty big investment, both in terms of money and space.

They’re not cheap to buy or maintain, and you’ll need a fair bit of room to set one up properly.

But if you’ve got the space and the budget for it, a 125 gallon fish tank can be a great addition to your home.

A 125 gallon fish tank is a pretty big tank! It can hold up to 10-12 average sized fish or 20-24 smaller fish.

This size tank is also a good choice for someone who wants to keep larger fish, like Oscars or plecos.

How Heavy is a 125 Gallon Fish Tank?

A 125 gallon fish tank is extremely heavy. The weight of the water itself is around 1022 lbs, and the weight of the glass is around 170 lbs.

That means that the total weight of a 125 gallon fish tank is around 1192 lbs!

How Big is a 120 Gallon Fish Tank?

A 120 gallon fish tank is a pretty big investment, so you want to make sure you do your research before making the purchase.

The average size of a 120 gallon fish tank is 12 feet long by 2.5 feet wide and 30 inches tall.

This size tank can accommodate a wide variety of different fish, as well as provide ample space for swimming and exploring.

How Many Fish Can Be in a 125?

A 125 gallon aquarium is a popular size for many fish enthusiasts. But how many fish can actually be safely housed in one of these tanks?

The answer, as with most things related to aquariums, depends on a number of factors.

The first factor to consider is the type of fish you want to keep. Some fish are much more active than others and require more space to swim.

Other fish are less active and can be kept in smaller quarters.

When making your stocking decisions, it’s important to research the specific needs of the species you’re interested in keeping.

Another important factor is water quality. Ammonia and nitrite levels must be closely monitored in any aquarium, but especially in a crowded one.

Overstocking an aquarium can lead to dangerous spikes in these levels, which can be deadly for your fish.

Regular water changes and diligent filter maintenance are essential when keeping a densely stocked tank.

Finally, you’ll need to take into account the personality of your fish when deciding how many to keep in a 125 gallon tank.

Some species do well in groups while others prefer to live alone or in pairs.

Keeping incompatible fish together can lead to aggression and other problems, so it’s important that you choose wisely when stocking your tank.

In general, a good rule of thumb is 1-2 gallons per adult fish for active swimmers and 1 gallon per adultfish for less active species.

This means that a 125 gallon aquarium could comfortably house anywhere from 12-25 adultfish depending on their individual needs.

Of course, this number will be lower if you’re also keeping juvenile or baby fish since they’ll grow into adults over time.

Ultimately, it’s up to you as the aquaristto decide how many fish your 125 gallon tank can support based on all of these factors.

How Many Gallons is a 24X12X12 Tank?

Assuming you are talking about an aquarium, a 24x12x12 tank would be approximately 96 gallons.

125 Gallon Fish Tank Empty Weight

A 125 gallon fish tank can weigh anywhere from 150 to 300 pounds when empty. The weight will depend on the type of material the tank is made out of.

For example, a glass tank will be on the heavier end while a plastic tank will be lighter.

Most tanks will come with a stand that must also be taken into account when determining the overall weight of the setup.

A 125 gallon fish tank is a pretty big fish tank. It can hold a lot of fish and it will look great in your home.


Fish tanks that are more than 100 gallons capacity are ideal for those who have space to spare.

With this setup, you can create an underwater ecosystem that will impress your friends and family with its beauty.

To set up this aquarium with the appropriate care and attention, you don’t need any specialized expertise or experience.

Just a little patience and persistence are all that are required to see incredible results.

Your fish will not only thrive, but they will also remain healthy if you don’t forget to change their water frequently!