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Welcome, new aquarists! Your role in this community is vital. In this chapter, we will be introducing to you the types of aquatic habitats that you can set up for your fishes, shrimps and snails but first of all, what is an ‘aquarium’? The etymology of the word ‘aquarium’ comes from the words ‘aqua’ (meaning ‘water’ in Latin) and ‘vivarium’ (meaning ‘place of life’ in Latin). Therefore, the word ‘aquarium’ is a portmanteau which means “a place/habitat for aquatic life to exist.”
Alright, fancy introductions aside, the main takeaway from the definition of an ‘aquarium’ is that it must be able to support life. Add water to the picture, and it now becomes apparent that the aquatic world is indeed vastly different from that of our terrestrial world. Underwater life processes take place differently. That is why we introduced this guide with a basic understanding of water chemistry.
Now, without further ado let’s take a look at the 9 (10, including a quarantine aquarium) types of commonly encountered freshwater aquariums; as well as the pros and cons of each type. They are:
By definition, a community aquarium also known as a community tank is a display tank which features a collection of various tropical / coldwater fishes that hail from different habitats across the globe and they can be housed together upon meeting a few basic premises.
Researching the temperament of your chosen species and their natural behavior is essential before heading down to your favorite local fish store for a procurement. Certain species of fishes are docile and should only be kept with conspecifics of similar temperament, e.g., cardinal tetras, and harlequin rasboras will school together in peace. More boisterous types of fish, such as tiger barbs, for example, are better off housed with, say, a small school of clown loaches or other medium-sized barbs that can reach up to 20 cm in total length when fully matured, despite the tiger barb’s relatively diminutive size of only 5 cm in total length.
Another aspect of compatibility concerns the predatory nature of a species – even supposedly “peaceful” species. For example, while a collection of neon tetras and fully grown adult angelfish may seem to evoke an idyllic, tranquil Amazonian river-inspired community, in reality, angelfish will gladly hunt down a neon tetra, shrimp or other similarly built, small fish species that can fit its mouth.
Always research a fish’s behavior well. The internet or, better yet, a well-written book on aquarium fish husbandry will often provide vital information you can use as a guideline for deciding your next purchase. While aquarium store staff can also be a source of valuable information for a more in-depth point of reference, nothing proves more dependable than a good quality book, which you can also add to your archives for future reference and inspiration. Moving forward, That Aquarium will also share our experience through this website, Learning Community, to guide you through the aquarium-keeping journey. Stay tune for our update!
Do the fish species you intend to combine share a similar pH and GH range?
Remember, if you cannot meet all of the fish species’ water parameter requirements, your aquariums will not be able to house your intended mix of fish. For instance, guppies prefer hard water with an alkaline pH, and thus, combining them with a fish species that demands soft, acidic water, such as wild-caught discus fish, will prove detrimental to the latter species.
Also, does their preferred water temperature range match?
Discus fish, for example, are tropical fish by nature. Keeping them at lower (tropical) temperatures in a planted tank aquarium is not advisable since their physiological needs differ from those of coldwater fishes. Yes, Discus may survive in cold temperatures. Still, for optimal health and vitality, it must be housed in an aquarium, a community tank with water temperatures above 27°C.
In a community setting, providing a varied and well-balanced diet to the tank’s inhabitants is vital to survival.
Most fishes are omnivores that will take a wide variety of dry and live/frozen food items. What is important to note, however, is to ensure that one more of your tank inhabitants are not being deprived of food due to faster or more aggressive fishes hoovering up their share.
This also correlates to a fish’s natural feeding mode, e.g., certain species, such as catfishes, are nocturnal in habit. Thus, during daylight hours, the fish may shy away from food, necessitating the addition of food to feast on at night.
Once again, researching your intended tankmates’ dietary habits is paramount in ensuring a successful and thriving community aquarium.
Nothing can feel more debilitating for the new aquarist than seeing an otherwise peaceful fish species outgrow its home in such a short time. Such is the case when the common pleco, which can reach a whopping 60 cm in total length when fully grown, can be seen stressing its smaller tankmates with a swipe of its extensive, armored tail.
Alas, the general rule of stocking community aquariums to adhere to would be to house no more than one inch of fish body length per gallon and, ideally, an aquarium at least ten times the fish’s body length. Granted, a single adult Oscar cichlid at 30 cm long can be housed comfortably in a 90 cm long tank, but it must be the only tank inhabitant.
More water volume equals more stable water parameters, and more tank space equals less stress, which means you enjoy viewing more of your fish’s natural pinnacle of enjoyment in this hobby!
So, dispel all misconceptions you may have heard about how aquarium fishes would supposedly never outgrow their tank size- that is a myth.
A fish’s cells are constantly replicating, which not only accounts for its regenerative properties, i.e., its ability to re-grow missing and frayed finnage but also means that a fish NEVER stops growing until its lifespan has been spent when it dies of old age.
Thus, properly caring for fish is a long-term commitment, so always opt for a combination of fish that can reach similar sizes, have identical lifespans, and avoid overcrowding your community tank at the get-go. No matter if the fish you have procured are male juveniles, The bigger the tank size, the better!
Get the biggest fish tank you can afford and aim to under-stock rather than overstock it. A glass tank that is much longer horizontally than it is taller would be best since such dimensions offer more real estate for the same volume. Plus, the lower the tank’s height, the better the gaseous exchange rates will be, helping to ensure that your aquarium water maintains optimal oxygen levels for your fish’s well-being.
In a mixed community tank, an aquarium filter is the heart that keeps the aquarium thriving. Thus, invest in the largest capacity filtration that you can afford.
At the top of the tech chain are the canister filters. The best and most advanced filters available today are canister filters that sit outside your aquarium (usually in the tank cabinet) and thus minimize visual obstructions while offering powerful, efficient filtration customized to your aquarium’s needs. Its only downside is cost, which pays dividends in the long run when considering its high performance meets minimal fuss to maintain.
Alternatively, you can opt for a suitably sized internal power filter that sits inside your aquarium with suction cups that secure it in place. Easy to install but somewhat laborious to disguise in an aquarium, the internal power filter offers good filtration and circulation for a fraction of the price of a canister filter.
We recommend an overhead top filter and sump system for more high-bioload hobbyist’s fish, as they provide the tanks with more aeration for the fish and nitrifying bacteria and give bio-media capacity volume and flexibility.
All filtration systems have their strengths and weaknesses, and the choice depends on the aquarium setup’s specific needs, the tank’s size, and the aquarist’s preferences.
As a plus point, the internal filter is a lifesaver in the event of a power outage since it sits inside your aquarium, where the filter’s beneficial bacteria should survive until power has been restored.
Comparatively, the beneficial bacteria in a canister filter would soon perish in the absence of oxygenated water circulating through its media chamber since the entire filter unit sits outside the aquarium and relies on gravity and pump circulation to operate normally. In such an instance, the internal power filter is a clear winner.
Hang-on-the-back (H.O.B.) filters, another viable option for a community tank, offer a unique adaptability. First popularized in North America, these filters come in various makes and models, from rudimentary designs to sophisticated upgrades featuring a rotating “bio-wheel.”
The H.O.B. is a small box that sits atop an aquarium, drawing water from the tank into the filter chamber via an intake tube and then returning the filtered water into the tank. This adaptability allows you to customize your filter media configuration, giving you control over your tank’s filtration system.
Price-wise, H.O.B. is relatively affordable and offers you the option to customize your filter media configuration.
Performance-wise, the H.O.B. filter has two jarring disadvantages. Firstly, its media chamber is small, which offers little room for more filter media. This means there is less biological filtration capacity relative to the aquarium volume. There is a way around this issue, and that is via the incorporation of an “auxiliary” filtration in the form of either:
a) an under gravel filter (U.G.F.), which optimizes the entire aquarium substrate’s bio-filtration capacity or,
b) a supplementary air-driven sponge filter that creates more biological filtration sites in the aquarium itself.
Secondly, the H.O.B. filter’s final drawback stems from pushing water through the filter media instead of an internal power filter/canister filter that draws in (pulls) water through the filter media. This seemingly trivial difference has a tremendous effect on the efficiency and longevity of the biofiltration component.
Water takes the path of least resistance, and when pushed against solid filtration media, it will bypass and flow around the media, creating dead zones. This further reduces the H.O.B. filter’s biofiltration efficacy over time if it is not serviced promptly.
Proper oxygenation is vital to ensure that your aquarium fishes have their biochemical oxygen demons (B.O.D.) met in the limited confines of a community tank.
Typically, additional aeration via an air pump would not be necessary in an under-stocked community aquarium. Otherwise, introducing an air stone or a sponge filter hooked up to an air pump is essential.
A lack of oxygen, especially during hotter weather (warm water holds less oxygen compared to cooler water at the same volume), can cause stress in fish.
The symptoms include rapid gill movements, gasping at the water surface, or, in severe cases, even death by hypoxia (insufficient levels of oxygen at lethal levels).
There are plenty of options regarding the material used to build the bed layer of your community aquarium.
In a generic community tank, aquarium gravel will suffice. Choose inert types of Gravel when going substrate hunting, i.e., Gravel that does not contain calcareous aggregate materials such as coral grit that can cause your pH and GH levels to spike upwards; this can stress acidophilic fish species but is otherwise ideal for hard water-loving species (alkaliphiles) such as livebearers, Central American and Rift Valley Cichlids.
How much Gravel would you need? A total volume of 4.5L of Gravel is plenty for a 30cmx30cm area of tank floor; e.g., a tank measuring 60cmx30cmx36cm needs 9L of Gravel. Substrates tend to be sold by weight instead of volume.
Lastly, choose a gravel with a particle size from the 3mm-5mm range. Too large Gravel can trap uneaten food and organic waste that decays in the deeper layers of your gravel bed. This creates noxious substrate conditions detrimental to water quality and fish health.
A gravel vacuum, or simply a gravel vac, is a device in the form of a clear plastic cylinder connected to a flexible hose, and its primary function is to hoover up trapped debris in your gravel bed; come the time to do your routine water changes.
For beginners and pros alike, a gravel vac is an essential maintenance procedure to differentiate between a healthy substrate and optimal water quality or a putrid substrate and degraded water quality for sick fishes in a community aquarium.
Aquarium plants come from a diverse group of families and even more varied species, but essentially; there are only two types of plants that the new hobbyist has to be acquainted with:
a) demanding aquarium plants that demand optimal growing conditions, and,
b) hardy, undemanding aquarium plants that are a doddle to care for, they need no special requirements and would do well in a generic community aquarium with a plain gravel layer.
Plants such as Java Fern, Anubias spp, Jungle Val (Vallisneria spp.), Hornwort, Water Trumpets aka Crypts (Cryptocoryne spp.), Hydrilla, Ludwigia Palustris, Java Moss and various species of floating plants will do well being housed in a community tank setting and given time, may thrive once they are thoroughly acclimated to your tank conditions.
However, two points of caution are warranted here: do not keep aquarium plants with burrowing fish or purchase non-aquatic plants at the fish store meant for terrarium or terrestrial use. Indeed, these plants will eventually perish in your aquarium, decay, and cause water quality issues. Continuously research, and if unsure, feel free to check with our That Aquarium staff at our retail stores.
For a community aquarium, generic daylight with a color temperature of 6500K to 6700K will suffice.
The ‘K’ accompanying the numbers indicates its Kelvin rating- a unit for measuring the color temperature (e.g., blue light in the range of 10 000K is suitable for marine aquariums where, whereas red light in the range of 4000K is ideal for aquatic plant photosynthesis) but daylight emits better overall color spectrum in a visually pleasing, balanced output.
Aim for light coverage for optimal viewing pleasure and even light distribution to encourage photosynthesis of aquatic plants in the aquarium (if any). When at the dealer’s outlet, specify to the staff that you are looking for medium light intensity. Which will suffice for a community tank housing hardy, undemanding aquarium plants.
What defines a “nano aquarium”?
And what kind of livestock can you house successfully in a nano aquarium? When an aquarium has a total volume below 60L (i.e., a standard 60cmx30cmx36cm tank), we call that a nano aquarium. Essentially, it is a small aquarium. Any aquarium up to 3L to 50L in volume is a nano aquarium, aka a nano tank.
If an aquarium were less than 3L in volume, we call it a pico-tank.
The rule of thumb with nano-aquariums is that the smaller the aquarium, the harder it becomes to sustain it in the long run. So, why even set up a nano-tank?
Contrary to a common misconception, the primary purpose of a nano aquarium is not just to save space. Instead, it’s a sanctuary for our pets.
When we set up an aquarium, the needs and welfare of our livestock should always come first. Nano tanks play a crucial role in providing a safe refuge for diminutive fish and invertebrate species that would struggle in larger quarters with more aggressive or unsuitable tankmates.
Here are a few examples. Galaxy rasboras are missing out on a large tank at mealtime because bigger, faster-swimming fish gobble up all their food before reaching the bottom domain. Shy and reclusive fish species such as the Burmese Rosy Loach or Argentine pearl killifish risk being predated upon by larger fish tankmates. These are valid reasons for housing livestock in a nano-aquarium.
That depends.
If setting up a nano tank for housing fish species that require still water, such as small killifish species that origins from vegetation-choked, stagnant pools, then a dense growth of aquatic plants without an aquarium filter would best meet the species’ needs as the species prefer stagnant water. When the nano aquarium serves as a miniature planted aquascape, and the fish dwell in it have more exacting demands for good water quality, then a small filter or even surface skimmer powered by a submersible pump will be useful. Again, you must first understand the core requirements of your intended fish species research.
Fishes, shrimps, and mollusks that reach a maximum adult size of under 3 cm in total length are the most appropriate candidates for a nano aquarium. Do exercise discretion regarding stacking levels, as nano tanks are also not immune to overstocking!
Aim for sensible stocking densities, e.g., a trio of Argentine pearl killifish in a 30L tank instead of a pair of cockatoo dwarf cichlids that grow larger and produce more waste.
Remember, the smaller the tank water volume, the harder it is to sustain it in the long run. Set up-wise, a nano aquarium is variable. It can be anything from a down-scaled planted aquascape to a miniature community aquarium of diminutive fish species, so there is no one-size-fits-all approach to setting up a nano tank.
Moving on from nano aquariums, we now touch upon the species aquarium. A species aquarium can be defined as a dedicated tank for a single, intraspecific (not interspecific) species of aquarium inhabitant.
The reasons for a species specific aquarium are numerous. Some fish species, such as the intriguing snakeheads (Channa spp.), are notorious for their solitary, pugnacious, and territorial nature, making them poor candidates for a community setting.
Other fish species may have very exacting demands with regards to water quality e.g. liquorice gouramis and / or are too sensitive to be kept with other fish species for fear of disease transmissions. Thus, these types of finicky fishes belong in their own safe refuge, away from contact with other species.
Perhaps the most compelling reason for setting up a species aquarium is their high conservation value / endangered status; many species of wild bettas of S.E. Asia face the threat of extinction due to illegal logging activities that destroy their native forest habitats at an alarming rate. An example is Betta Persephone, a diminutive freshwater/peat swap species known only from the Ayer Hitam area of Johor State, S. Malaysia.
The layout process should center around the physiological needs of your chosen species. For example, a breeding colony of zebra plecos can be housed in an over-filtered, well-aerated aquarium designed to emulate the rocky outcrops of its native Rio Xingu riverbed. Or, perhaps a sluggish, heavily planted aquarium featuring black water for a pair of wild-caught dwarf cichlids from the forests of Brazil or Cameroon. The best part of setting up a dedicated species tank is that the aquarium can be aesthetically pleasing on top of being tailored to the needs of your fish, which lends itself an air of novelty that sets it apart from a generic community tank.
The biotope aquarium, often considered the most controversial type, presents a unique challenge in its conception and unconventional husbandry techniques. It is a geographically-correct representation of a given habitat found in the wild, re-imagined and re-created in your aquarium. This unique challenge sets it apart from other types of aquariums.
Here, particular emphasis is given to the accuracy of the tank layout above its aesthetic appeal. Everything from the color and texture of the substrate material to fish species and aquatic plants (if any), rocks, wood, and even the use of dried tree leaves native to the actual habitat concerns the biotope tank. Indeed, it is slavishly detailed, and “cheating” (e.g., use of aquatic plants not native to the habitat in situ) is prohibited. The Biotope Aquarium Design Contest judges, who are well-traveled to even the most remote habitats, have provided detailed video recordings of their explorations in situ.
As expected, a true biotope aquarium is for the seasoned, hardcore aquarium connoisseur to attempt; the amount of research into pulling off an accurate biotope layout would dissuade the new hobbyists.
Who would balk at the sight of rotting tree leaves littering the tank bottom? Many newcomers erroneously presume that any aquarium featuring black water and a “dirty” look is a biotope aquarium. Or otherwise, set up a generic, ambiguous “South American Biotope Tank”. These are not biotope tanks. Merely natural aquariums bridge the gap between personal whim and a tinge of Mother Nature’s chaos. There is nothing innately wrong in setting up such aquariums, but do not confuse that for an authentic biotope aquarium.
Ultimately, a biotope aquarium featuring the authentic look of Earth’s countless natural underwater habitats may not be everyone’s cup of tea due to the effort it demands.
A planted aquarium is unlike a regular fish tank in terms of its goals and conception. The main focus of a planted tank is to achieve healthy plant growth and a healthy ecosystem that can manage its nutrient levels (i.e., trophic levels) well. It is Science meets Art, and one must recognize the technical aspects of running a successfully planted aquarium. So brace yourself as we guide you deeper into the inner workings of a deceptively calm and tranquil-looking planted aquarium.
What is a planted aquarium? And what does “low tech / high tech” even mean? Before we even talk about plants and the gadgets required to have a flourishing planted tank, the first thing that one must understand is Liebig’s Law of Minimum, which states that when all necessary limiting factors are present, achieving a state of equilibrium becomes possible. Does this sound too daunting? Don’t worry! It is a straightforward concept to understand with the aid of this diagram.
The diagram illustrates the three limiting factors necessary for plant growth: light, CO2, and nutrients.
All of these must be present to support good plant growth. Yet, the most critical limiting factor is light. Why? Light is the energy source that drives photosynthesis in plants, a process whereby plants make food and, thus, live when their light requirements are met. Therefore, a low-tech/high-tech plant is chiefly determined by how much light the tank can provide for the plants.
As light intensity increases, so do the demands for Co2 and nutrients. It’s a simple cause-and-effect relationship. This means you have the power to decide whether you want a low-tech, low maintenance planted tank or a high-tech, high maintenance one filled with vibrant, but demanding, aquarium plants. Your choice of lighting will determine this.
Plants are carbon-based life forms. They need a carbon source to make food and grow it. Providing a constant carbon source is easy in a high-tech planted tank with medium to high light intensity. Simply injecting pressured Co2 gas (via a regulator) directly into the aquarium water column. This practice, however, may feel daunting to a beginner hobbyist.
In its conception, a paludarium is a hybrid between an aquarium and a terrarium. It features an area that is part land and part water. While impressive visually, the actual water volume within a paludarium is significantly reduced vis a vis an aquarium of the same size and dimensions. Thus, special consideration must be given to appropriate fish stocking levels to avoid rapid water quality degradation. The paludarium is, overall, dominated by terrestrial plants, with little regard given to the aquatic section of the display in most cases.
A separate, dedicated aquarium is furnished to stimulate the fish spawning behavior of captive aquarium broodstock. A typical breeding tank is utilitarian in its function, and thus, little value is placed on its aesthetic appeal. Instead, its Sportan design aids the target species in reaching objectivity. To breed, hence a layer of marbles or spawning mop fabricated from nylon yarn is deployed for free-spawning egg-scatterers, or a piece of slate is placed partially buried in the sand for open water spawners such as a pair of Oscar cichlids to take advantage of.
Every species adopts its spawning rituals; thus, a breeding tank must be modular in design to cater to the fish’s needs, allowing quick disinfection of spawning tools. A gentle air-powered sponge filter is usually deployed in a breeding tank. When not intended for fish breeding, a spawning tank can also be used as a quarantine/hospital tank.
Aquascaping is the art of using hardscape materials (natural rocks and driftwood) to create an aesthetically pleasing layout. Typically, aquascaping is deployed in planted aquariums to maximize its visual impact by using the golden ratio to create optically balanced underwater landscapes.
Made famous by the late Takashi Amano, an aquascape can represent Nature on a small (but grand) scale through clever placement of hardscape materials to evoke a mountainous diorama, a lush forest or simply an abstract underwater scenery. The possibilities are endless, but for the beginner, understanding and applying layout composition theory is key. This knowledge, combined with practice from attending aquascaping seminars / workshops, will prepare you for your aquascaping journey.
Alternatively, the aquascaping series can be contracted for a reasonable fee if a hands-free approach to an aquascaped tank, including its long-term maintenance, is desired.
The 9 common types of freshwater aquariums are as follows:
Each type of aquarium has its own unique setup and maintenance requirements, making it important for you to research and choose the right type for your and your aquatic pets need. For more in-depth learning, feel free to check with our That Aquarium staff at our retail stores.
Proudly presented by our That Aquarium Digital Team, where innovation meets aquatic excellence.
Published on 13 June 2025
Author: Saufi
Illustrator(s): Jolin Lee, Nor Haliza, Chai Minyu, Kelvin Phua, Abbie Tan
At That Aquarium, we believe that exceptional CARE is the foundation of our success. We are committed to treating each customer and every aquatic life with genuine compassion and respect. Our dedication goes beyond providing quality products and services; we strive to create a nurturing environment that delivers a therapeutic experience for our customers, our aquatic life, and our team. Guided by principles of integrity, forward-thinking mindset, and continuous improvement, we aim to foster a harmonious and supportive atmosphere. Our focus is on ensuring that every interaction reflects our dedication to excellence and our care for both our people and our community.
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