Start with a rectangular, lidded betta fish tank of at least five US gallons for one fish, plus a heater, a gentle filter and a separate thermometer. Then check the kit against the list below before you pay: the tank is only the beginning, and the filter has to be cycled before a fish goes in.
A betta tank buying and setup checklist
Use this as a shopping and setup list. It is written for one betta; if you are planning tank mates or a larger display, size up.
- Tank: at least 5 US gallons (about 19 L) for one betta, with a rectangular footprint and a secure lid. Aqueon's lifespan guide recommends at least five gallons with a heater and filter, low-flow filtration and 76–81°F (24–27°C) water.
- Heater: rated for the tank's volume, preset or adjustable.
- Thermometer: separate from the heater, so you can verify the temperature yourself.
- Filter: gentle or adjustable flow, with biological media. If it is an air-driven sponge filter, add an air pump, tubing and a check valve.
- Lid: included and fitting securely. Aqueon's setup guide notes that bettas are known jumpers.
- Water conditioner: a dechlorinator for tap water. Petco's beginner guide, dated July 16, 2026, recommends conditioning tap water before use.
- Test kit: ammonia, nitrite, nitrate and pH. Petco's guide also recommends checking water quality with a test kit.
- Decor: live or soft plants, a hide, and smooth wood or rock. Petco suggests plants that do not snag fins.
- Cycling supplies: a fishless ammonia source, plus a bottled nitrifying-bacteria product if you choose to use one. Follow the label for both.
- Maintenance basics: a bucket, siphon, net and a log for test results.
- Stand: level, solid and rated for the filled weight.
Before you leave the store, open the box or read the contents list and confirm which of those items are actually included. A kit that lacks a heater, thermometer, test kit or conditioner is not a complete starter setup.
Five or ten gallons: what you get for the extra water
Five gallons is the smallest starting point we would recommend for one betta. Aqueon's lifespan guide calls for at least five gallons with a heater and filter, and the same page recommends low-flow filtration and 76–81°F. That is a documented manufacturer recommendation, not a universal biological minimum; published care guides disagree about the true floor, so treat five gallons as a practical starting point. Sea Life Planet's betta care guide also treats five gallons as the minimum and lists the species' target water parameters: pH 6.5–7.5, ammonia and nitrite at 0 ppm, nitrate below 20 ppm and 2–15 dGH.
Ten gallons (about 38 L) is not automatically better for the fish, but it is more forgiving. The extra volume gives you more usable swimming space, more room to fit a heater and filter without crowding, and a slower rise in waste between water changes. It also opens the option of a snail or a small group of shrimp, though the betta may still eat them. The trade-offs are real: a ten-gallon tank weighs more filled, needs a sturdier stand, costs more to equip, and takes more water per change.
Footprint matters as much as the number on the box. A long, shallow tank gives a betta more horizontal swimming space than a tall column of the same volume, and it is easier to reach into for maintenance. Measure the space you have, including room for the filter and lid, and check that the stand is rated for the filled weight.
Neither five nor ten gallons guarantees a healthy fish. The heater, filter, cycle and maintenance do the work; the tank size only sets how much margin you have.
What a starter kit includes, and what it leaves out
Kit contents vary, so read the contents list rather than assuming. A typical kit may include the tank, lid, light and filter, and sometimes a heater. The common gaps are a separate thermometer, a test kit, water conditioner, decor, a stand, and the air pump needed by an air-driven sponge filter.
Filter. Look for adjustable flow or a design you can baffle. Petco's beginner guide also advises gentle filtration. A filter that pushes a long-finned betta around is too strong. A sponge filter driven by air is a valid choice, but it needs its pump, tubing and a check valve; without the pump it is just a sponge in the water. Aeration alone does not filter the tank.
Heater and thermometer. Check the heater's rating for the tank volume and whether it is preset or adjustable. Pair it with a separate thermometer. The heater's dial is a setting, not a measurement.
Lid. The lid should fit securely, leave about an inch of air between the water line and the lid, and have a small feeding opening. Aqueon's setup guide recommends a sturdy cover because bettas can jump, especially after a water change or a disturbance.
Conditioner and test kit. Tap water needs dechlorination before it goes in. Petco's beginner guide also recommends checking water quality with a test kit; get tests for ammonia, nitrite, nitrate and pH. Choose a kit you can read consistently, because you will use the ammonia and nitrite tests most during the first weeks.
Decor. Live or soft plants, a hide and smooth wood or rock are safer than sharp plastic plants. Petco's guide recommends plants that do not snag fins. Leave open swimming space at the front and a clear gap under the lid.
Light. Match the light to the plants you keep. Six to eight hours a day is a common starting point; reduce it if algae grows faster than the plants.
Shape, lid and stand
Shape. A rectangular tank with a wide top is easier to light, filter and work in than a tall column or a narrow-mouthed bowl. At the same volume, a long footprint gives the fish more usable space.
Lid. A lid is not optional. It keeps a jumping betta in the tank and slows heat loss and evaporation. Leave a gap between the water line and the lid so the fish can reach the surface.
Stand. Plan for the filled weight, not the empty tank. Water, substrate and rock add up quickly. The stand needs to be level and solid, and the tank should stay out of direct sun and away from radiators.
Equipment that earns its place
Filter. The filter's main job is to house the bacteria that process ammonia and nitrite. Choose one with biological media and gentle, adjustable flow. Rinse the media in water taken out during a water change, not under the tap, and do not replace all the media at once.
Heater. A betta is a tropical fish. Aqueon recommends 76–81°F (24–27°C); aim for the middle of that range and verify it with your own thermometer. In most homes, an unheated tank sits below the comfortable range, especially overnight.
Air pump. An air pump belongs in some betta tanks. If you use an air-driven sponge filter, the pump is what moves water through the sponge, so you need it. If you use a different filter, an airstone can add surface movement, but it does not replace filtration, and a strong stream can add unwanted current. Adjust or baffle it.
Test kit. Ammonia, nitrite, nitrate and pH. During the first weeks, the ammonia and nitrite tests are the ones you will use most.
Water conditioner. A dechlorinator is the basic chemistry purchase. Follow the label for the volume of water you are treating.
Setting up a betta fish tank, step by step
- Place the tank on a level, solid stand away from direct sun and drafts. Add a foam mat under rimless glass if the manufacturer calls for one.
- Rinse the substrate until the water runs clear, then add an inch or two.
- Arrange the plants, wood and hide, leaving open swimming space and a gap under the lid.
- Fill with dechlorinated water. Pour onto a plate to avoid stirring up the substrate, and stop about an inch below the rim.
- Install the filter and heater. If you are using an air-driven sponge filter, connect the pump, tubing and check valve. Start the equipment and check that water is moving.
- Check the temperature with the separate thermometer, not the heater's dial.
- Cycle the tank before adding a fish. The next section covers what that means.
- Acclimate the fish slowly: float the container for 15–20 minutes, add tank water gradually, then release the fish with a net or a cup. Do not pour store water into the tank.
- Feed lightly for the first week and test every couple of days. Once ammonia and nitrite stay at zero, move to a routine based on your test results.
Cycling: how you know the tank is ready
Running an empty tank does not establish the biological filter. The nitrifying bacteria need an ammonia source to grow. Dr Tim's fishless cycling guide puts it plainly: just setting up the tank and turning the filter on will not establish the bacteria; ammonia has to be added. The guide describes a fishless cycle using ammonium chloride with One & Only Live Nitrifying Bacteria, but the principle applies to any fishless protocol: add an ammonia source according to the product's directions, then test.
Follow the directions for the specific product or protocol you choose. Do not invent a dose, and do not add a chemical you cannot measure. The tank is ready when the system processes the ammonia you add and leaves nitrate with no detectable nitrite. Dr Tim's guide says to confirm that all the ammonia is converted to nitrate with no trace of nitrite within 24 hours before adding fish. Use your own test kit to confirm that in your tank.
Two false signals are common. Zero ammonia and zero nitrite in clean water with no waste load do not prove the filter is mature, because there was nothing for it to process. Nitrate appearing on its own is not proof either. Neither is running the filter for 24 hours, or counting a fixed number of days. Cycling can take weeks; a bottled bacteria product may shorten it, but the test result is the gate.
Keep the filter running and the temperature stable during the cycle. Do not replace all the filter media, and do not tear the tank down because the water looks cloudy; cloudiness is common while a new tank settles.
Where first betta tanks go wrong
Bettas are labyrinth fish, which lets them gulp air at the surface when oxygen is low. That adaptation is why a betta can stay alive in a small, unfiltered container long enough to be sold, and why "it survived" is not a test of whether a setup works.
No heater. A betta in room-temperature water often sits at the edge of its range, and a cold night can become a health event. Use a heater and a separate thermometer.
A bowl or a very small tank. A bowl or a one-gallon tank leaves little room for a heater and filter, and the temperature can swing quickly. It is not a setup we would recommend, even if a fish can survive in it for a while.
An uncycled filter. Adding a fish to a brand-new tank means managing an ammonia spike instead of preventing one. Cycle first.
Buying a kit without reading the contents. A kit that lacks a heater, thermometer, test kit or conditioner is not a complete setup.
Overfeeding. Uneaten food decays into ammonia. Feed only what disappears in a couple of minutes, once or twice a day.
Rinsing filter media under the tap. Chlorinated water can kill the bacteria the filter is meant to house. Rinse the media in water removed during a water change.
A full teardown "clean." Scrubbing everything resets the tank toward day one. Regular partial water changes and a gentle siphon do most of the work.
Strong current. A filter that pushes the fish around is exhausting it. Baffle the outlet or choose a gentler filter.
Tank mates in a five-gallon. A five-gallon tank is a one-betta setup in practice. A snail or some shrimp may work, but the betta may eat them, and both add to the bioload.
Household cleaners and soap. Rinse anything that goes into the tank with water only.
Tank mates, plants and long-term maintenance
A betta on its own is a complete setup, not a compromise. It is also the simplest way to avoid compatibility problems. If you want more company, start with a ten-gallon tank. Avoid known fin-nippers such as tiger barbs and serpae tetras, other bettas, and goldfish, which need cooler water and produce much more waste.
Snails and shrimp often work in a planted tank, but a betta may treat shrimp as a snack, and both add to the load the filter has to handle. For plants, start with low-light species that tolerate a simple light and no added carbon dioxide. Floating plants are useful: they shade the tank, give the fish cover and take up nitrate. Our planted aquarium setup guide covers the basics.
Water changes are a response to what the tank is producing, not a fixed ritual. Test ammonia, nitrite and nitrate, and change enough water, often enough, to keep those values where they should be. For a single betta in a filtered five-gallon tank, a 25 percent change once a week is a common starting routine, but it is not a guarantee and not the right schedule for every tank. A larger tank, a lightly stocked tank or a heavily planted tank may need less; a smaller tank or a heavy feeder may need more. Let the tests and the stocking decide. The aquarium water quality guide explains what each test result is telling you.
One Aqueon staff member's five-gallon MiniBow journal is a useful illustration of why the calendar alone is not enough. The author was surprised by how much brown debris collected in the filter cartridge—more than the water itself suggested—and moved from the suggested monthly change to weekly changes. That is one keeper's observation in one brand-published diary, not an independent test or a universal schedule to copy. It is a reminder to check the filter and the test results, not just the day of the week.
Siphon the substrate during water changes, rinse the filter media in the old tank water, and keep a short written log of test results. A log makes a rising nitrate trend easier to catch than memory does. If a fish stops eating, gasps at the surface or shows frayed fins, test the water first and review our fish disease guide before adding medication.
Common follow-up questions
Is five gallons really enough for a betta? For one betta, five gallons is a practical starting size, provided the tank is heated, filtered, cycled and maintained. If you want more margin or tank mates, ten gallons is the better starting point.
Does a betta tank need a heater? In most homes, yes. Aqueon recommends 76–81°F (24–27°C), which is warmer than typical room temperature. An unheated tank leaves the fish at the edge of its range with little buffer against a cold night.
How long does a betta fish tank take to cycle? It can take weeks, and the time varies with the method, temperature and how much ammonia you add. Do not count days. Follow the fishless-cycle protocol you chose and test: the tank is ready when a full ammonia dose is processed to nitrate with no detectable nitrite.
How often should I change the water? There is no single schedule that fits every tank. Test ammonia, nitrite and nitrate; for a single betta in a filtered five-gallon, a 25 percent weekly change is a common starting point, then adjust based on the results and the stocking.
Can I keep a betta in a bowl if I change the water often? We would not recommend it. Frequent changes can lower ammonia, but a bowl leaves little room for a heater and filter and the temperature can swing quickly. A five-gallon tank is the smallest practical starting point for most keepers.
Does a betta fish tank need an air pump? Only if you use an air-driven sponge filter, or if you want extra surface movement. A pump alone does not filter the water. If you choose a sponge filter, you need the pump, tubing and a check valve to run it.
What tank mates can go in a five-gallon? In practice, a five-gallon is a one-betta tank. A snail or some shrimp may work, but the betta may eat them. If you want more options, start at ten gallons and choose species that are not fin-nippers and do not resemble another betta.
