33 Gallon Long Aquarium (The Dimensions & Stocking ideas)

33 gallon long aquarium

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It’s no secret that the size of an aquarium is directly related to the type of fish you’d want to breed.

When it comes to medium-sized aquariums, the 33 gallon long variant is preferred by fishkeepers worldwide. But before we address the question: “how long is a 33 gallon long aquarium?” it’s important to understand why it may be a good choice in the first place.

And that’s what we will tell you in today’s guide.

33 Gallon Long Aquarium Dimensions

As far as the dimensions are concerned, a 33-gallon long aquarium measures about 48 inches long, 12 inches wide, and 12 inches high. It weighs approximately 52 pounds when empty and 380 pounds when filled, including the weight of the frame.

Tank SizeL x W x HEmpty Weight Filled Weight
33 Gallon Long 48″ x 12″ x 12″ 48 lbs348 lbs
55 Gallon48″ x 12“ x 21”78 lbs625 lbs

Now, you may be wondering why people may opt for this variant instead of a bigger one, like a 55-gallon long tank. Well, one of the main reasons is that a 33-gallon long aquarium weighs about 200 pounds less than its 55-gallon counterpart. So, it’s suitable for placement on cabinets and fixtures that may have a low load-bearing capacity.

Moreover, its short height usually gives the illusion of a longer frame, which may look aesthetically pleasing. Some fishkeepers also consider it to be a better hill stream setup compared to a 55-gallon long aquarium.

Why A 33 Long Aquarium Is Better?

Weight And Same Footprint

As we have already mentioned, the weight of a 33-gallon long aquarium is less than a 55-gallon aquarium. However, both have the same footprint, meaning you can use one as a replacement for the other as long as it has the right environment for the fish.

Better For Low Light Aquarium Plants

The height of bigger aquariums (like 50-gallon or 55-gallon long tanks) can hinder the amount of sunlight that reaches the plants. Especially if the aquarium doesn’t receive enough sunlight, it can be difficult to direct all of it towards them.

But thanks to the short height of the 33-gallon long aquariums, you can rest assured that your greens will receive optimum sunlight. This means that you don’t need to add any fancy or powerful lighting per se, which will cut down on the setup costs.

Easy To Set Up A Divided Tank

Whether you’re dividing a tank using physical or behavioral division techniques, longer tanks (like a 55-gallon one) will be difficult to divide. And the task can get even more challenging if you’re a first-timer, setting up a shrimp tank with aggressive species, such as male bettas.

However, the low height of a 33-gallon long tank will make it easier for you to reach the base of the tank without putting too much strain on your arms. 

Less Maintenance

Compared to smaller aquariums, like a 10-gallon or 20-gallon, a 33-gallon tank is easier to maintain. This is because the former are often overstuffed with livestock, which ultimately leads to more waste accumulation.

On the other hand, water changes in a 33-gallon long aquarium will take less time than in a bigger tank. So, we’d say that it’s quite a win-win situation!

33 Long Aquarium Stocking Ideas

Plants for a 33-Gallon Long Tank

There are many live plants you can keep in your 33-gallon long aquarium, but not all species will survive or thrive. It’s also dependent on your preference, you should avoid stem plants for an open style aquarium tank or if you don’t want to trim things too much. Not to mention that a 33 long tank is easy to illuminate, which is not ideal for stem plants. While for jungle style aquariums, having beautiful stem plants is an ideal choice for the background.

Below I’ve listed few selected aquatic plant species so they thrive in their new home.

Java Ferns And Mosses

Java ferns comprise tapered oval-shaped green leaves growing from the rootstalk. In aquariums, they can grow between 25 and 30cm high to form dense greenery and are widely used for ornamentation purposes. Plus, you don’t have to trim them very often.

Likewise, Java mosses are low light/low tech plants and have a soft stem of about 17 cm. They also have a thick covering of pointed leaves and are suitable for use as spawning substrates for fishes as well as decoration.

Rotala Rotundifolia ‘Ceylon’

Originating from Sri Lanka, the Rotala Rotundifolia is a fast-growing stem plant that is commonplace for aquariums. Not only are they easy to grow, but they can also survive in different types of water conditions.

One plant may consist of 6 to 8 stems with narrow, light-green leaves, which may later turn pink when exposed to strong light. It’s usually grown as bushes in the area between the midground and foreground.

Anubias Barteri Var ‘Nana’

Anubias Barteri Var ‘Nana’ is another “hardy” species that’s ideal for freshwater aquariums. This tiny plant grows to a height of about 6 inches and has a firm texture with deep green leaves and stems. The leaves are about 1.5 to 3.5 inches long and 1.5 inches wide, with the overall height being 6 inches.

Besides, this plant can grow in low light conditions without CO2 injection. In fact, it tends to develop problems if subjected to powerful lighting.

Pogostemon Erectus

The Pogostemon Erectus has a distinct blend of green stems and yellow needle-thin tipped leaves. It has an overall compact form and can grow vertically between 15 and 40 cm.

Their compact structure makes them perfect for use as a background bush, creating an aesthetically pleasing focal point for both small and large aquariums. However, they need continuous intense lighting for optimum development.

Crypt Spiralis

One of the earliest cultivated aquarium plants, Crypt Spiralis, has maintained its popularity among scape lovers. This plant features corkscrew-shaped long leaves that have a distinct hammered texture, making them a great additional accent for the mid or background bushes.

Despite being relatively easy to grow, they do have specific requirements, like a consistent water condition and CO2 injection. Apart from that, frequent transportation can hamper their growth, so make sure you don’t move them once planted inside the aquarium.

Fish for a 33-Gallon Long Aquarium

Every aquarist has their preferred fish, but it is important to know the requirements of each for a happy and healthy life. Most schooling aquarium fish or more peaceful slower swimmers do well in a 33-gallon long aquarium, while other aggressive ones need a bigger tank for them to live comfortably.



Danios are a family of hunter/predator fishes that are generally peaceful and active swimmers, growing up to a size of about 2.5 inches. They are relatively easy to maintain and are suitable for beginner fish keepers on a restricted budget. Plus, there are different danios species that come in different colors, sizes, and shapes.

One thing to keep in mind is that these fish prefer living in an environment with fresh, long-lasting plants.

Guppies And Platies


Guppies and platies are two of the most common aquarium fishes that are kept together. Although the males of both these types can get aggressive from time to time, they are generally peace-loving varieties that can coexist with other peaceful fishes.

Platies, in particular, are known to be active breeders, and the males can become aggressive towards the females during the breeding season. 

Neon Tetras

Neon Tetra​

You will probably find neon tetras in almost every pet store, as the small and colorful fish are extremely convenient to care for by beginners. They sport a neon-bright stripe on the upper half of their bodies and a vibrant-red stripe below their silver bellies, which extend to the tail.

Neon tetras are schooling fish, so you should ideally create a small shoal in at least 10 gallons of water. And they usually grow between 1 and 1.5 inches in aquariums.


If you have a freshwater aquarium, then you may opt for gourami. Their tall and wide bodies have beautifully patterned scales, which make them look like vibrant gemstones in the water. Similar to danios, there are different gourami species, which come in a range of colors and sizes.

Moreover, the different species have different levels of temperament. So, we’d suggest keeping them in male-female pairs with other fish of the same temperament level.

Black Mollies

Black mollies owe their striking black color to the lack of pigmentation, but some of them can have a dash of yellow on the dorsal fin. They are best reared in large aquariums (at least 20-gallon) and require stable water conditions.

However, the good news is that they can thrive in different environments, including freshwater and saltwater aquariums.

Lighting For A 33 Long Aquarium

Before we wrap up this guide, here are a few lighting options that you can try out:

Coralife Aqualight T5 Dual Lamp Fixture

This Coralife lamp fixture is made from one high-output 10,000K daylight lamp and one actinic lamp, both of which are more powerful than the traditional T8 lamps. It has a simple yet sturdy powder-coated aluminum housing and acrylic splash guards to shield the lamps from damages.

Additionally, it features adjustable mounting guards and is suited for both freshwater and saltwater aquariums.

Fluval Plant 3.0 Aquarium Lighting

Featuring 120-degree coverage, the Fluval plant aquarium lighting consists of 6 band waves to facilitate full-spectrum lighting. Moreover, it has a programmable 24-hour setting for gradual lighting throughout the day.

The pack also includes extendable mounting brackets for easy installation in aquariums of different widths.

Odyssea T5 Dual 6500K Aquarium Light

Primarily designed for freshwater aquariums, this Odyssea model has a sleek design and T5 bulbs that are easy to replace. It has an output of about 7,000 lumens, which is suitable for small to medium-sized aquariums.

Besides, it has external ballasts, which prevent the risk of overheating the aquarium. And the extendable brackets can be flipped if you opt for under-screen mounting.

Final Thoughts

With that, it’s time for us to wrap up.

But before you head out to set up a 33-gallon aquarium, ensure that you cater to the specific requirements of both the plants and fish. And always keep the water clean to facilitate maximum development of the livestock.

We will see you next time!

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Gabriel R

Gabriel R

Welcome to Aquarium Fish City(AFC). I’m Gabriel and I have been keeping fish for almost fifteen years. My father was a huge fan of tropical fish and our childhood home had a huge aquarium which he tended and kept hundreds of species of fish over the years. I was always fascinated by our fish tank and would spend hours staring at the fish. They seemed to all have different personalities and would interact differently with one another. Here, you can find out everything you need to know about keeping fish and aquarium maintenance.

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