How to Choose an Aquarium (Beginner Set) | By Animals, Size and Filtration
Prices, point rates and sale details in this article were checked by the mottoku editorial team against each service's official site and API (as of the last update). Always check the official sites for current prices, stock and campaign terms.
You are not buying a box. You are buying a small aquatic ecosystem
Maybe it started with a single goldfish from a festival scoop game, or with a wish to watch green aquatic plants sway in the living room. Everyone enters the aquarium hobby differently. But the moment you open a store or an online shop, tanks, filters, lights, heaters, dechlorinator and substrate all appear at once, and it is easy to get lost about what to base your choices on.
The first thing to change is your mindset: what you buy with an aquarium is not a glass box but the small aquatic ecosystem you grow inside it. Waste and leftover food from fish and shrimp foul the water, and it is invisible bacteria that break them down. The first few weeks, before those bacteria settle in, are the biggest hurdle of the hobby. If you start without knowing this, you step into the most common failure of all: putting every fish in on day one and losing them all within a week. So when choosing equipment, work backward from "can I secure a water volume suited to the animals I will keep?" and "can the filtration keep up with that volume and those animals?" before you look at appearance or what comes in the set.
This article is not a ranking of specific products. It summarizes general ideas for beginners choosing aquarium supplies. Because this hobby means taking responsibility for living creatures, always research the care, lifespan and required environment of a species before you bring it home, and consult a specialist or aquarium shop when in doubt. Prices and specifications change by time and store, so we recommend confirming them in store or with official information in the end.
If you are unsure, start here: within the space you have, choose a slightly larger tank (as a guide, about 45 to 60 cm wide). More water keeps water quality and temperature steadier, and the failure rate drops, especially for beginners. For goldfish or medaka, a room-temperature set works; for tropical fish, pick a set with a heater and thermometer. And before adding fish, run the tank with water only for one to several weeks (this is called cycling the tank). This one extra step largely decides how things turn out.
"Smaller is easier" is a myth | Water volume creates stability
The very first misunderstanding beginners fall into is "a small tank saves space and must be easier to manage." In fact the opposite is true: the less water there is, the faster water quality and temperature swing, and the harder it gets. A glass of water clouds and warms up quickly, while a bucket of water barely changes. The same happens in a tank.
Tanks are named by their width, such as "a 60 cm tank," and the water volume changes roughly as follows. The larger the volume, the more waste and leftover food get diluted in the water, and the less the tank is affected by room temperature.
| Size name | Approx. water volume | Suitable animals / where to place it |
|---|---|---|
| 20-30 cm (small) | A few to a dozen or so liters | A few medaka, small shrimp, bettas. Fits on a desk, but water quality is hard to manage |
| 45cm | About 30 liters | An all-rounder for beginners. A good fit for schools of small tropical fish and planted layouts |
| 60 cm (standard size) | About 60 liters | The most widely sold size, with the widest range of equipment. The standard size for properly enjoying goldfish or tropical fish |
| 90 cm or more | Over 150 liters | Large fish and serious planted tanks. Weight and installation become serious, and it is too heavy for a beginner's first tank |
What people tend to overlook here is weight. One liter of water weighs about 1 kg. A 60 cm tank holds 60 kg of water alone, and with sand, glass and the stand it can exceed 80 kg. That is like an adult's whole body weight resting on one spot, and if you put it on a wobbly color box or a flat-pack piece of furniture, in the worst case the water floods the floor along with it. Deciding the water volume also means deciding the strength of the place you put it and the load capacity of the floor. Keeping this in mind before choosing a set saves you from the regret of buying a tank you cannot place.
In a rental, the weight of a tank can put a heavy load on the floor depending on its structure. If you are considering a large tank, assume you will use a dedicated aquarium stand (cabinet) that spreads the weight over the contact surface, and consult your property manager if you have concerns. A window with direct sunlight causes heavy algae growth and higher water temperature in summer, so a spot along a wall away from it is safer.
The biggest hurdle, cycling the tank | Do not add fish right away
What makes an aquarium fundamentally different from appliances or daily goods is that you cannot use it at its real performance right after buying it. A tank is at its most dangerous right after you set it up and fill it with water. The bacteria that neutralize ammonia, which is harmful to fish, have not yet grown enough in the filter and the substrate.
This preparation period for growing the bacteria is called "cycling the tank". Here is how it works: the highly toxic ammonia from fish waste and leftover food is converted by bacteria into nitrite, and then another group of bacteria converts it into nitrate, which is comparatively less harmful, step by step. Only when this cooperation of filter bacteria (the nitrogen cycle) starts running does the tank become an environment where animals can live safely. It takes roughly one to several weeks to get going. Whether you can wait is what separates beginners who stay with the hobby from those who give up.
The rough flow of cycling
- Set up the equipment and fill with waterInstall the tank, filter, substrate and (if needed) heater, add dechlorinated water, and start running the filter.
- Run it for a few days to a week without fishThe key is not to add animals at this stage. Commercial bacteria products can sometimes help the cycle along.
- Add only a few hardy animalsDo not add all the ones you really want at once; start with just a few. Their waste feeds the bacteria and helps them multiply.
- Increase gradually while watching water qualityAdd animals over several weeks. If you are worried, checking ammonia and nitrite with test strips gives peace of mind.
"Putting all the goldfish from the festival scoop game into a brand-new tank on the day you buy them" is the most common failure pattern. The cycle is not ready in time, and within days the fish suffer ammonia poisoning. On the day you bring them home, first acclimate them in a bucket or small container with dechlorinated water to tide them over for a few days, and set up the main tank in parallel. Just knowing this routine saves many more lives.
Types of filters | The real star of choosing a tank
When looking at set products, your eyes tend to go to how the tank looks, but the heart of an aquarium is the filter. The bacteria from the previous chapter mainly live inside the filter. So choosing a filter directly determines how stable your water quality will be and how easy the maintenance is. Let us go through the main types.
| Type | Features | Suited tanks / people |
|---|---|---|
| Drop-in (air-driven) | Inexpensive and simple in structure. Driven by an air pump, which also supplies oxygen. Modest filtering power | Small tanks, goldfish, people who just want to get started |
| Top filter | Sits on top of the tank. A standard choice with high filtering power and easy cleaning. Somewhat noisy and bulky | 60 cm standard size, fish that foul the water such as goldfish |
| Hang-on filter | Easy to hook onto the rim. Simple to install and popular for small to medium tanks. Modest filter media capacity | Around 45 cm, easy for a desktop |
| Canister filter (closed) | Powerful filtration in a tank outside the aquarium. Quiet and a good match for planted layouts. Price and installation are somewhat more serious | Planted layouts, those who value quiet, serious hobbyists |
| Sponge filter | Gentle suction that is unlikely to catch baby shrimp and fry | Shrimp, breeding, small tanks |
There are three points to weigh when choosing. The first is filtering capacity for the water volume and animals. For fish that foul the water like goldfish, or when you keep many, a filter with room to spare (top or canister) gives peace of mind. The second is quietness. In a bedroom, the buzzing of an air pump or the sound of flowing water is surprisingly noticeable. Canister filters are quiet, but the price goes up. The third is ease of cleaning. The media inside a filter must be rinsed from time to time, and here the rule is that scrubbing with tap water kills the bacteria you worked to grow, so rinse lightly in tank water.
The filter in an all-in-one set suits beginners in that it gets "everything you need in one go," but its filtering power can fall short as you add animals. If you want several goldfish from the start or want to raise them big, consider a separately bought filter one grade stronger than the one in the set (such as a top filter) to cut down on wasted purchases later.
Equipment depends on the animals you keep | Routes by type
The starting point of choosing a tank is always "what will you keep?" Even within the same hobby, goldfish, medaka, tropical fish and shrimp need entirely different sizes, temperatures and equipment. Deciding the animals first and working backward to the right environment looks like a detour but is the shortest path.
Goldfish | Can live at room temperature, but grow bigger and foul the water more than expected
Festival goldfish suit beginners in the sense that they can be kept at room temperature (often no heater needed). The thing that tends to be a miscalculation is that goldfish grow surprisingly large, eat a lot and excrete a lot, which means they foul the water. Keeping several in a small goldfish bowl quickly ruins the water. The secret to keeping them healthy for a long time is to prepare at least a 45 to 60 cm class tank and filtration with room to spare, such as a top filter.
Medaka | Small, and enjoyable even in a biotope. A beginner species
Medaka can be kept in small tanks or in lotus bowls on the balcony (biotopes), and they are a staple: hardy and fun to breed. When keeping them outdoors, watch for high water temperature and evaporation in summer and freezing in winter. Indoors, a small to medium tank with gentle filtration is enough. Room-temperature keeping is the basic approach, but they are weak against sudden temperature changes, so be careful where you place the tank.
Tropical fish | Vividly colored and unmatched to look at. A heater is essential
If you want to enjoy brightly colored red and blue tropical fish, a heater to keep the temperature constant and a thermometer are essential. Each species has different suitable temperatures, water quality and compatibility with tank mates, so research before keeping them is indispensable. Water quality management weighs heavily, so the key to success is keeping up filtration and water changes and adding animals little by little. Adding a heater to an all-in-one set is an easy configuration to start with.
Shrimp and aquatic plants | Delicate, but deep once you get hooked
Shrimp such as Neocaridina (Japanese cherry-type) shrimp are also popular as algae eaters, but they are sensitive to changes in water quality and to chemicals. Sponge filters with gentle suction are a good match, and for planted layouts a closed canister filter and a dedicated LED look their best. The difficulty goes up, so getting used to making water with hardy fish first makes it easier not to give up.
How to judge an all-in-one set | Read what is behind the low price
What is handy for beginners is the all-in-one set, in which the tank, filter, lights and so on come in one box. There is little worry about compatibility, and as a first step it is rational. However, if you buy without looking at the contents just because it is a set, you may keep having to buy more later. Do not be swayed by price; check the following points on the back of the box or on the product page.
- Are a heater and thermometer included? If you plan to keep tropical fish but the set is a "room-temperature set," you will need to buy them separately. Always check that it suits your animals.
- Filter type and filtering power: Many are small hang-on or drop-in types. If you keep many fish that foul the water, they tend to fall short.
- Is the light LED, and is the brightness adjustable or timer-compatible? Brightness matters if you want to grow plants. Leaving the light on all the time causes algae, so being able to adjust it is handy.
- Is dechlorinator, filter media or bacteria product included? Consumables are often sold separately. Check that what you need for cycling is there.
- Does the tank size suit the place and purpose? A small desktop tank is easy to start with, but management is demanding. If you want to keep it long term, a slightly bigger one turns out easier in the end.
Conversely, if you seriously want to keep fish for the long term, a smart configuration is to use the set as a base and swap only the filter and heater for something one grade better. The weak points of cheap sets are usually the filter and the bundled heater, so shifting your budget there changes your satisfaction a great deal.
Before you head to checkout, confirm in this order
Aquarium supplies are a typical case where you find what is missing only after buying. Even if the tank itself arrives first, you cannot add fish until the filter, heater and dechlorinator are all in place. Checking in the following order makes gaps less likely.
- Decide the load capacity of the place firstA 60 cm standard tank exceeds 60 kg once filled with water and gravel. On a color box or an ordinary shelf, the top panel sags and in the worst case breaks. If you get this wrong, you will not just rebuy a tank; you will rebuy the furniture too.
- Measure the tank's outer dimensions and the placement surfaceThe "60 cm" on a product page is mostly the standard size (around 60 x 30 x 36 cm), but the outer dimensions are larger by the frame. If it fits the inner width of a shelf with no room to spare, the filter and cords at the back will not fit through.
- The filter's suitable water volumeDoes a label like "for 45-60 cm" leave room for the actual water volume of your tank? If you are at the lower limit, the water turns cloudy white when you add animals.
- Whether a heater is needed, and its wattageEssential for tropical fish; in principle unnecessary for goldfish and medaka. Wattage is decided by water volume and the room's lowest temperature. If it is too small, it will not reach the set temperature in winter.
- Compatibility with the lid and the lightTanks without a lid risk fish jumping out. If you use a top filter or a hang-on filter, also check whether the lid has a cutout.
- Consumables needed on day oneDechlorinator, thermometer, bucket and net. Without these, you cannot take the first step of cycling.
Decide on animals last. If you follow the order of judging "how many can I add" after the equipment is in place and the water is ready, you avoid unreasonable overstocking.
Canister, top, hang-on or drop-in: which to choose
Starter sets almost always come with a hang-on or drop-in filter, but depending on tank size and what you keep, choosing a different type from the start can end up saving effort.
| Type | Guide to filtering power | Sound / look | Suited conditions |
|---|---|---|---|
| Hang-on | Modest | Quiet but splashes easily | 30-45 cm with a few small fish. For people who want to get started |
| Top filter | High (strong aerobic filtration) | Water-falling sound. The top surface is blocked | 60 cm or more, fish that foul the water like goldfish |
| Canister | High | Quiet. The area around the tank stays tidy | Planted tanks, CO2 injection, appearance-focused setups |
| Drop-in (with an air pump) | Low to medium | The pump makes vibration noise | Medaka, fry, supplementary filtration, quarantine tanks |
| Under-gravel | Medium to high (gravel acts as media) | Almost silent | Assumes a thick gravel layer. Be careful about compatibility with plant roots |
The ones people most often hesitate over are the top filter and the canister. For fish that excrete a lot such as goldfish, a top filter that takes in oxygen easily is easier to handle, and you can reach the media from above when changing it. On the other hand, if you want to grow plants, avoid losing CO2, or want quiet operation, choose a canister. Because the canister body goes inside the stand, check the cabinet's inner dimensions and the hose routing first.
Replacing the filter that came with a set later is not unusual, and in that case, if you move the media with established bacteria into the new filter, you do not have to redo the cycle. This works even when the type of filter changes.
Things people tend to do during cycling, and what happens next
Aquarium failures usually start with "something done with good intentions." They are especially concentrated in the first month.
- Changing all the water because it is cloudy: Cloudiness often happens as bacteria multiply, and a full water change sends you back to square one. Limit yourself to a partial change of about one third, and rinse the media and sponge in tank water, not tap water.
- Feeding many times because the fish beg for food: Leftover food and waste are the main source of ammonia. Right after setup, feed once a day, only what is eaten in a few minutes. Healthy adult fish do not suffer from a few days without food; rather, they can endure it.
- Pouring the water from the bag you bought them in into the tank: If you only match the temperature, differences in pH and hardness can cause shock. Float the bag to match temperature, mix in tank water little by little, then move only the fish with a net.
- Burying the heater in gravel or laying it on its side: This can cause dry firing or local overheating. Choose one with a cover and fix it horizontally where water flow reaches it.
- Relying on chemicals when algae appears: In most cases the cause is one of these: the light is on too long, too much food, or too few water changes. Limiting lighting to about eight hours a day with a timer works better.
- Releasing surplus fish or plants into a nearby river: Some species fall under Japan's Invasive Alien Species Act, and the effect on native ecosystems can be irreversible. The only prevention is to design your tank so that they do not multiply.
Rather than reacting after symptoms appear, it is more reliable to keep a thermometer and test kits that measure ammonia and nitrite at hand from the start. When you can see the numbers, you can tell "it is not yet time to add fish."
What "L/h," "W" and "standard size" on a product page mean
Aquarium spec sheets use many unusual notations, and whether you can read them changes how accurately you compare.
| Notation | Meaning | What to look at when comparing |
|---|---|---|
| Standard tank / standard size | Common standard dimensions with high circulation, such as 60 cm x 30 cm x 36 cm | Lids, lights and top filters are easier to reuse. Odd sizes make finding replacement parts a struggle |
| L/h (flow per hour) | The amount of water the pump pushes in one hour | About 5 to 10 times the water volume is one guideline. Some plant species dislike a flow that is too strong |
| W (watts) | Heat output of the heater | The required amount varies with water volume and the room's lowest temperature. Too large is less likely to cause problems |
| Fixed-temperature heater / separate thermostat | Fixed temperature type, or one where temperature can be set | If you want to raise the temperature to treat illness, choose a separate type. Fixed types cannot change the setting |
| Mechanical / biological / chemical filtration | Strains out debris / bacteria break things down / activated carbon and the like adsorb | If the set's media is only one sheet of activated carbon mat, there is not enough place for biological filtration |
| Ra / lm (lighting) | Color rendering and brightness | Brightness matters for growing plants, color rendering for display |
| Suitable tank size | The tank width the manufacturer assumes | Different fish species make different amounts of waste, so for goldfish there is room to pick one class up |
The most commonly misread is "suitable tank size." This is not a guarantee that it is always enough for that tank, but a guideline that assumes a standard stocking density. Even in the same 60 cm tank, a dozen or so small tetras and three goldfish foul the water at completely different speeds.
Measurement points to prevent "it won't fit, it can't go there, it can't reach"
Once a tank has water in it, it cannot be moved. Here are the physical conditions to decide before installation.
Floor and stand
A 60 cm standard tank weighs over 60 kg, and a 90 cm tank around 150 kg. Choose a dedicated aquarium stand or furniture of similar strength, and check that none of the tank's four sides overhangs the stand. A rimless tank must be supported by its whole bottom, so the flatness of the stand's top matters too. On tatami or carpet the tank tilts as it sinks, so put a board underneath to level it.
Clearance around it
A hang-on filter needs a few centimeters at the back, and a top filter needs space above for maintenance. With a canister filter, the bending radius of the hoses and the height and depth inside the stand become issues. If you want it right against a wall, add up these rear dimensions first.
Power and outlets
Filter, heater, light, air pump, plus a warmer in winter and a cooling fan in summer: the number of outlets runs short quickly. Always let cords hang down in a loop lower than the outlet (so drips do not run along them) and avoid places where water can splash. Use a power strip with enough capacity and, if possible, a splash-proof one.
Sunlight, air conditioning and vibration
A window with direct sunlight causes algae to explode and brings water temperature up to dangerous levels in summer. Directly under an air conditioner's outlet, temperature swings are also large. Next to a washing machine or near a door, vibration and the shock of opening and closing keep fish from settling. Also consider whether the route for carrying buckets for refilling and water changes is short, and you will keep the hobby going longer.
What to check right after delivery, and what is easy to miss in warranties
Aquarium goods arrive as glass, electrical products and living animals together, so the kinds of trouble also differ.
- Shipping damage to a glass tank: When unboxing, check the silicone seams at the corners and chips on the edges first. After use (once water is added), it is hard to tell whether the damage came from shipping or installation. Recording the unboxing speeds things up.
- Heater warranty period: For many products, besides the warranty period, a guide to lifespan such as "replacement recommended every year" is given. Even if the warranty has not expired, you need to decide to replace aged units early to prevent accidents. Damage from dry firing is generally excluded from warranty.
- Pump noise or leaks: There is a deadline for reporting initial defects, so as soon as it arrives, first do a stand-alone power test in a bucket filled with water. If you do it after installing on the tank, you will argue over whether the cause is the assembly or the unit itself.
- Missing items in a set: Check an all-in-one set against its included list and the actual contents. The smaller the item, such as a small packet of dechlorinator or suction cups, the later you notice it is missing.
- Live arrival guarantee: When buying fish or shrimp by mail order, many shops offer compensation on the condition that you send a photo within a set time after arrival. If you put off unboxing, you fall outside this condition.
Most stores state that a tank body "cannot be returned once water has been added." Think of right after unboxing as the last chance to notice a wrong size or color, and measure before adding water.
Where and when to buy | How to buy aquarium supplies
Aquarium supplies are best thought of in two groups: animals (fish, shrimp, plants) and equipment (tanks, filters, consumables). Instead of a generic "buy cheap at a sale," there are circumstances unique to this hobby.
Buy animals at a specialty shop, in person
For animals such as fish, shrimp and plants, a specialty shop or aquarium store where you can check their condition with your own eyes is the safer choice. You can see if they swim energetically, if there are signs of disease (white spots, damaged fins), and ask about species and compatibility on the spot, which is the strength of buying in person. The more of a beginner you are, the greater the value of a physical store where you can bring questions about cycling and care.
Equipment and consumables are convenient online, but mind weight and freshness
For equipment and consumables such as tanks, filters, sand and dechlorinator, online shopping is also strong on selection and price. But a tank is heavy, fragile glass, so check the packaging and shipping fee for delivery. For products containing live bacteria such as bacteria supplements, freshness affects quality, so choosing a store with fast turnover is safer.
When sales are worth aiming for, and how to buy by marketplace
If you are making a lump-sum initial investment in equipment, the big sales that come a few times a year are worth aiming for. If your timing allows, overlapping them with each e-commerce site's discount period can lower the initial cost.
| Where to buy | How it works for aquarium supplies |
|---|---|
| Rakuten Ichiba | With the Shopping Marathon campaign's buy-across-shops bonus, it is easy to stack points by combining tanks, sand and consumables from several shops. Many pet and aquarium specialty shops have storefronts |
| Amazon | Equipment discounts tend to appear during Prime Day, Black Friday and similar events. Heavy tanks are also easy to ship together. Check real-world quietness and usability in the reviews |
| Yahoo! Shopping | Grouping equipment purchases on PayPay-related reward campaign days makes it easy to lower the effective cost |
| Specialty shops (physical stores) | The first choice for animals, plants and initial consultation. You can also check compatibility before buying equipment |
Point reward rates and campaign conditions change by period. We do not state specific reward rates, conditions or whether annual fees apply; before buying, please check the latest details on each e-commerce site's and each card's official page. Adding candidates to your favorites before a sale and remembering the regular price lets you judge immediately whether it is truly cheap.
Rules for life and safety | Share them with your family before you start
Unlike an appliance, an aquarium involves living creatures. There are basic premises that take priority over convenience and looks. Before you buy, share them with your whole family if you can.
- Always remove chlorine first: The chlorine in tap water is harmful to bacteria and animals. Use dechlorinator before adding water to the tank.
- Change water a portion at a time, not suddenly: Changing all of it at once shifts water quality and temperature drastically and stresses the animals a lot. The basic approach is a partial change once a week.
- Do not overstock; add gradually: Exceeding the number you can keep makes the water worsen at once. Start with fewer, especially right after setup.
- Feed the right amount: Overfeeding makes leftover food foul the water and causes illness and algae.
- Never release animals into the wild: Releasing pets or non-native species into rivers or ponds destroys ecosystems and breaks the law. Take responsibility to the end, and if that is difficult, look for someone to take them.
- Prevent electrical and water accidents: Heaters, lights and pumps are electrical devices used near water. Watch for electric shock, leakage, heater dry firing (when the water level drops) and fire, and run cords to the outlet with a slack loop so drips cannot run down them.
- Prevent tipping and earthquake damage: Place a heavy tank on a sturdy, stable stand and prepare for tipping and leaks. Keep an eye on small children so they do not put their hands in or knock it over.
Caring for animals together with children is a good chance to learn the value of life and of "taking responsibility to the end." That said, assume that adults are at the center of the care. Before you start, research the animal's lifespan, required environment and size when grown, and consult an aquarium shop if you are unsure before bringing it home.
Frequently asked questions
Can I put goldfish from a festival scoop game straight into a brand-new tank?
No, that is the most common failure. A new tank has no grown bacteria, so ammonia is not broken down right after you add them. Acclimate them in dechlorinated water first to tide them over for a few days, set up the main tank in parallel, and move them once it has cycled, which is safest. Avoid putting them all in on the same day.
What is "cycling a tank"? How long does it take?
It is the preparation period for growing, in the filter and sand, the bacteria that break down ammonia harmful to fish. Run the filter with water only, and once water quality stabilizes after roughly one to several weeks, add animals gradually. Skipping this step makes it easy to lose animals to poor water quality right after setup, so waiting is the shortcut to success.
Isn't a smaller tank easier to manage?
It is the opposite. The smaller the tank, the less water it holds and the faster quality and temperature swing, so management actually gets harder. The more water, the more stable the environment, so within the space you have, a slightly larger tank (as a guide 45 to 60 cm class) is easier for beginners. Small desktop tanks look stylish, but choose one understanding that frequent upkeep is assumed.
Which type of filter should I choose?
Choose by filtering power matched to the water volume and animals. For ease, hang-on or drop-in; for fish that foul the water such as goldfish, a top filter; for quiet operation or planted layouts, a canister; and for shrimp and fry, a sponge filter. The filter is the heart of stable water quality, so prioritize "can it keep up with the water volume and animals" over low price.
Do goldfish and medaka need a heater?
Many goldfish and medaka species can be kept at room temperature, so it is not always required. But sudden temperature changes stress them, so be careful where you place the tank. Tropical fish, on the other hand, require a heater to keep the temperature constant and a thermometer. Look up the water temperature suited to your animals, and add equipment if needed.
If I buy an all-in-one set, do I need nothing else?
It is handy as a first set, but a heater, dechlorinator and filter media may be sold separately, and for tropical fish you may need additions. The filter in a set tends to run short of power as you add animals, so if you want to keep fish seriously for a long time, swapping the filter and heater for a grade better raises your satisfaction.
Where should I put the tank? How heavy is it?
Water weighs about 1 kg per liter, and a 60 cm tank can exceed 80 kg including sand and the stand. Put it on a stable, sturdy stand (ideally a dedicated cabinet) and avoid wobbly furniture. Direct sunlight causes algae and higher water temperature in summer, so along a wall is safer. A spot that makes water changes easy and is near an outlet is also easier to manage. In a rental, also consider the load on the floor.
What should I do when algae or cloudy water appears?
The main causes are too much light, overfeeding, insufficient filtration and too few water changes. Reviewing lighting time, feeding the right amount, changing water a portion at a time and cleaning the filter often improves things. You can also add algae-eating shrimp or snails, but research compatibility first. Sudden large water changes and medication are a burden, so go little by little. If it does not improve, consult a specialty shop.
What about when I am away from home for a few days?
Fish are surprisingly tolerant of fasting, and for a few days, if you set up the water quality beforehand, going without food is often fine (it depends on the species). If you are worried, use an automatic feeder or vacation food. But overfeeding fouls the water, so be careful. For longer trips, also consider whether a power outage would stop the filter and heater and whether someone can look after the tank, and make water checks before and after the trip a habit for peace of mind.
What should I do if I can no longer keep them?
Releasing them into a river or pond must never be done, because it destroys ecosystems and breaks the law. Taking responsibility for the animal to the end is the basic premise. If unavoidable circumstances arise, use appropriate means such as finding someone to take them or consulting an aquarium shop. Researching the animal's lifespan and adult size before bringing it home makes such situations easier to avoid.
Is there a way to supply ammonia when cycling a tank without fish?
There is a method called "fishless cycling" in which you add commercial ammonia solution or a small amount of food to deliberately create waste. Its advantage is that you can grow the bacteria without burdening any fish. A rule of thumb is to wait until a test kit detects neither ammonia nor nitrite, which generally takes several weeks.
My water gets too warm in summer. Is there anything besides a chiller?
Pointing an aquarium cooling fan at the water surface can lower the temperature by a few degrees through evaporative cooling. However, water evaporates steadily, so you must keep topping it up and watch for changes in specific gravity and water level. Shortening the lighting time, opening part of the lid to let air through, and keeping the room air conditioner running on low are also effective.
I will be away for a few days. How should I feed the fish?
Healthy adult fish are generally said to be fine without food for two to three days. Putting in extra actually worsens water quality. For longer trips, use an automatic feeder or a food block that dissolves slowly in water, and finish a partial water change and filter cleaning before leaving for peace of mind.
Is CO2 injection required to grow aquatic plants?
It is not required. If you choose species that grow without CO2, such as Anubias, Microsorum and hornwort, lighting alone can sustain them. CO2 pays off when you want to grow species that demand strong light and nutrients, such as foreground carpet plants or red plants. First stabilize the tank with hardy species, then decide whether to add equipment.
I am worried about the floor with a tank. Is it okay in an apartment building?
Floors in ordinary homes are designed for a certain live load, but a tank has a small contact area and the load concentrates. Up to about 60 cm, the basic approach is to put it on a dedicated stand along a wall or near a pillar. If you are considering 90 cm or more, consult your property manager beforehand about steps such as placing a board to widen the contact surface or checking the position of the beams.
* This article is for reference only. Sale dates, point rates and campaign terms can change, so check each store's official page for the latest details.