A GUIDE FOR NEW FISHKEEPERS ✦ STEP BY STEP
Your First
Betta Aquarium
Your first aquarium should be exciting, not overwhelming. We'll guide you through the important decisions in the right order—from choosing the tank to bringing your betta home.
No jargon · No guesswork · just friendly advice from people who love fish
New to Tropical Fish?
Love the idea of keeping tropical fish but not sure where to begin?
You're in the right place!
Most first-time fishkeepers ask the same questions: which tank should I buy, what does cycling mean, how do I know the water is safe, and when is the aquarium ready for a fish?
This guide takes you through the process in the correct order, using a betta aquarium as our recommended first set-up.
We'll explain everything, in plain English - so you can progress with confidence.
The first and most important lesson is simple: prepare your aquarium before choosing or ordering the fish.
In this guide, we explain not just what to do, but why it matters—because once you understand the reason behind each step, the whole process becomes easier and more enjoyable.
Everything in the setup and cycling sections applies to most tropical aquariums.
We use the Betta—one of our recommended first tropical fish—as the worked example throughout.
In this guide:
1. Is a betta right for you?
2. Choosing your aquarium & kit
(Buying the equipment you need)
3. Heating and Temperature
5. What does cycling actually mean?
8. Plants, hides and enrichment
9. Choosing a healthy betta
10. Preparing for delivery day
11. The first week
4. Choosing a Filter
6. Your cycling action plan
7. Checking the water is ready
12. Everyday Care starts here
(Settling your new betta in)
Part One
Choosing your first fish & tank
1.
Is a betta right for you?
Bettas are beautiful!. They are curious and highly individual fish. They can make an excellent first tropical fish because one betta can live successfully on its own, without the need to build a large community of different species.
Their daily care is straightforward once the aquarium has been properly prepared, but they are not bowl fish. A betta still needs adequate space, stable warm water, gentle filtration, cover and regular maintenance.
They're a good first choice because:
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they come in a wonderful range of colours and fin shapes;
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their day-to-day care is straightforward once the tank is properly set up;
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they're alert and interactive — they quickly learn feeding routines and come to greet you.
Our recommendation
For a permanent home, choose a 25–30 litre aquarium or larger, with a heater, a gentle filter, some plants and a place to shelter.
That's deliberately roomier than the bare minimum. A bigger body of water is also far more forgiving for a beginner, because the temperature and water chemistry change more slowly and gently — giving you time to notice and fix anything before it becomes a problem.
Science behind the advice
A 2024 study comparing male bettas in containers from 1.5 to 19.3 litres found them noticeably more active, with fewer abnormal behaviours, in the largest planted aquarium; separate work found at least 10 litres was needed for unrestricted swimming. No single study proves one "perfect" size — but the evidence consistently points the same way: larger, furnished aquariums support more natural activity and better welfare. Our 25–30 litre recommendation is a welfare standard built on that evidence, not a magic number.
Some fish are best left until later. Arowana and many channa (snakeheads) need much larger aquariums, specialist knowledge and more complex management. They are fascinating fish, but they are not suitable choices for a first aquarium.
2.
Choosing your Aquarium and kit
Here's what a good first aquarium contains
Now here's your shopping list. Don't be put off by the length — most of it is one-off kit you buy once and keep for years.
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Tank of around 25–30 litres or more, with a secure lid;
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Adjustable heater;
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Gentle filter;
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Thermometer (separate from the heater);
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Reliable water test kit covering ammonia, nitrite, nitrate and pH;
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Water conditioner;
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Smooth substrate (gravel or sand), plants and a cave or shelter;
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Suitable lighting;
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Good-quality betta food;
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A dedicated aquarium bucket and gravel cleaner/siphon, kept only for the tank.
A long, wide tank is better than a tall, narrow one. Bettas swim from side to side rather than up and down, and they need easy access to the surface — which a wide tank gives them plenty of.
Good to know: bettas have a special organ called a labyrinth organ that lets them gulp air from the surface — so you'll see yours pop up for a breath now and then. That's completely normal. It doesn't mean they can do without clean, filtered water, though — they still breathe through their gills too, and always need an open, unobstructed surface to reach.
Heating & temperature
3.
Bettas are tropical fish, so they need warm, stable water. Aim for:
24 -27 °C
A steady tropical temperature
Use an adjustable heater, and always double-check it with a separate thermometer — heaters aren't always accurate, and the thermometer tells you the real temperature. Keep the tank away from radiators, windows and draughty doorways, where the temperature would swing about.
Here's the key idea: stability matters more than chasing a perfect number. A steady 25–26°C is far better than water bouncing between 24 and 28. Fish are cold-blooded, so the water temperature drives their body temperature, digestion and immune system. Sudden swings are stressful; steadiness keeps them well.
Choosing a Filter
4.
Your filter does much more than catch visible bits of dirt, it has two different components doing two different jobs. 1. Mechanical media, the sponges and floss, physically strain debris out of the water. 2. Biological media, usually ceramic rings, bio-balls or sintered blocks, are there to house the bacteria that convert ammonia to nitrite and then nitrite to nitrate. So a filter isn't optional; it's the engine room of a healthy tank. See our Easy Guide to Tank Cycling for more details
Good gentle options include:
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a sponge filter;
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a small internal filter with adjustable flow;
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any filter you can soften or baffle to reduce the current.
The reason for "gentle" is that bettas, especially the long-finned ones, aren't built to battle a strong current all day. The flow is right when your fish can swim, feed and rest without being pushed around.
Important: never switch the filter off at night. The helpful microbes living inside it need a constant supply of oxygenated water — turn it off and they start to die, which undoes all the good work.
Part Two
Cycling: the most important step
This is the bit beginners skip and regret. Don't skip it.
Before you buy anything, we recommend you read this summary and also our complete Tank Cycling Guide. Cycling is truly the step that decides whether your first fish thrives or struggles.
What does "cycling" actually mean?
5.
This is the single most important idea in the whole guide, so let's take it slowly.
Fish constantly produce waste, and leftover food breaks down too. This releases a chemical called ammonia, which is highly toxic to fish — even small amounts are dangerous.
The good news is that nature has a solution. Given time, colonies of beneficial microorganisms grow in your filter and turn that toxic ammonia into something far safer, in two steps:
ammonia → nitrite → nitrate
Nitrification, carried out by beneficial microorganisms
Ammonia and nitrite are both harmful. Nitrate much less so and is controlled through regular water changes and plant growth. “Cycling” means establishing the biological filter before your fish moves in, so the aquarium can process waste safely from day one.
A safe aquarium keeps ammonia and nitrite at zero while the fish is producing waste.
Our complete Tank Cycling Guide walks you through what you have to do — worth reading now before you start.
6.
Your Cycling Action Plan
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Set up the aquarium with the filter, heater, substrate, plants and décor.
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Fill it with conditioned tap water.
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Add a measured aquarium-grade ammonia source.
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Test ammonia and nitrite regularly.
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Continue until the aquarium can repeatedly process the required ammonia dose to zero ammonia and zero nitrite within about 24 hours.
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Carry out a water change if needed to reduce nitrate before the fish arrives.
Before buying or ordering your betta:
Simply running the tank for several weeks does not prove that it is cycled. Readiness must be confirmed by testing.
Patience pays off: cycling typically takes a few weeks, and it can't be rushed. Adding mature filter material from a healthy, disease-free established aquarium, or a bottled bacteria starter, can speed it up — but you still need to test, because every tank is a little different and your new arrivals life depends on it.
Checking the water is ready
7.
A dependable test kit is one of your most important tools. It must measure ammonia, nitrite, nitrate and pH. Liquid kits are a popular choice, and some test strips are useful too. Check the contents carefully: many strips do not measure ammonia. Both ammonia and nitrite are essential readings during cycling, and nitrite can remain dangerously high after ammonia begins to fall. Record the results so you can see the pattern clearly.
A properly cycled, safe tank has the following parameters:
One last thing on pH: resist the urge to add chemicals to force it to a "perfect" number. For bettas, a stable pH is far safer than one you keep adjusting. Steady beats ideal, every time.
For the full testing schedule and final 24-hour challenge, see the Tank Cycling Guide.
Part Three
Making your Tank Suitable for a Betta
The fun part — once the groundwork's done.
Plants, hides and enrichment
8.
A planted, furnished tank isn't just prettier — it gives your fish choices: places to explore, shaded spots to rest, cover to feel safe. Bettas in furnished tanks behave more naturally and show fewer signs of stress than those in bare ones.
Easy beginner plants include Anubias, Java fern, Java moss, Cryptocoryne and floating plants.
Anubias and Java fern should be attached to wood or rock rather than buried deeply in the substrate. Their thick horizontal rhizome should remain exposed.
Aim for a balance of plants, shelter and open water. The aquarium should feel secure without becoming cluttered.
Aim for a mix of cover and open swimming space, with a resting spot or two near the surface, since bettas like to rest somewhere they can easily reach the air.
9.
Choosing a healthy betta
When it's finally time to choose your fish, look past the colour for a moment and check it's healthy. A good betta is:
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alert and responsive to movement;
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swimming in a controlled way;
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holding its fins naturally;
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free of white spots, ulcers or cotton-like growths;
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neither thin nor swollen;
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breathing calmly, without obvious distress.
For a first betta, shorter-finned forms are often the easiest — they swim more efficiently and their fins are less prone to tearing. Short-finned Plakats and many females are generally efficient swimmers and may be less prone to fin damage. A healthy veiltail can also make an excellent first betta, kept with gentle flow and smooth furnishings. Don't choose on colour alone — a healthy fish in a plainer colour will give you far more joy than a stunning but sickly one.
See our Guide to the different Betta forms for more information on tail types.
Part Four
Preparation for Delivery Day
Settling your new Betta in
10.
One absolute rule for beginners: never house two male bettas together. Male bettas are territorial and can seriously injure one another. Never keep two males together in the same undivided tank.
Travel is stressful for fish, so the aim now is calm. Before your betta arrives, do a final check: tank fully cycled, temperature right, water tested, lid secure, and dim the lights to keep things soothing.
Now discard the Transport Water - DO NOT USE!
Once your betta is in, leave it in peace to settle. It's completely normal for a new fish to hide, look a little subdued, or ignore food for the first day or two. Resist the urge to fuss — calm and quiet is exactly what it needs. Offer a tiny bit of food once it's swimming about confidently, and remove anything it doesn't eat.
These are the essentials. The full Betta Care Guide explains delivery-day checks, first feeding and what to expect while the fish settles.
The First Week
11.
Give your betta time to settle. Some begin exploring and feeding quickly; others remain quiet for a day or two.
During the first week:
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keep the temperature stable;
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keep lighting subdued at first;
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feed lightly once the fish is swimming normally and showing interest;
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remove uneaten food;
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test ammonia and nitrite daily;
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check that the filter is running properly;
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observe breathing, swimming, colour and appetite.
Ammonia or Nitrite Detected?
Change 25–50% of the water immediately using dechlorinated water at a similar temperature. Retest afterwards and repeat if necessary. Check the filter and remove any uneaten food. Do not wait for the normal weekly water-change day.
Questions about settling-in, feeding or general wellbeing? See our Fish Health & Welfare Guide or contact Kieran for general advice.
Part Five
What Comes Next..
12.
Everyday Care Starts Here
Once your betta has settled, long-term care becomes a simple routine of observation, feeding, water changes, filter care and enrichment.
The full Betta Care Guide covers:
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feeding;
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lighting;
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plants and enrichment;
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tank mates;
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weekly maintenance;
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healthy signs and warning signs;
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common mistakes.
Your Final Checklist
You Are Ready When:
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the aquarium is 25–30 litres or larger;
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the heater and filter are running correctly;
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temperature is stable at 24–27 °C;
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the cycle has been confirmed by testing;
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ammonia and nitrite are zero;
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nitrate is controlled;
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the tank has shelter, plants and open swimming space;
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the lid is secure;
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food and maintenance equipment are ready;
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someone will be present for delivery.
Prepare first, choose carefully and let your betta settle calmly. That is the foundation of successful fishkeeping.
And most of all, enjoy yourself!
