How to Set Up a Betta Fish Tank: Equipment and Steps

The short answer

Get a tank sized for one betta (sources give 2.5 to 5 gallons or more), a secure lid, a low-flow filter and a heater. Add fin-safe decor, fill with conditioned water, prime and start the filter, then the heater after its wait. Cycle the tank (sources describe fishless and fish-in ways) and float-acclimate the betta (Aqueon’s method).

This guide is for one betta alone in a freshwater tank; our fish tank set-up guide covers placing, leveling and filling any tank. Aqueon is an aquarium-products maker; PetMD’s care sheet is vet-written; Tree of Life is an exotic-pet vet clinic; the University of Illinois vet college column quotes a zoological-medicine vet, Dr. Krista Keller.

What you need

A tank (sizes below) and a lid. Aqueon’s betta setup article says bettas “can unintentionally jump out of a tank without a cover. So, make sure your tank has a secure lid.”
A low-flow filter. The Illinois column: “A low-flow filter is vital to ensure that the fish’s delicate fins are not injured by the suction of a filter.” PetMD: “Air-driven sponge filters or box filters or very low flow rate filters are ideal for bettas.” Our filter current guide covers turning one down.
A heater and thermometer. PetMD: “Select a heater that provides about 3–5 watts per gallon.”
Water conditioner and a test kit, both on PetMD’s supply checklist.
Decor, plants and substrate (step 2).
Betta food (step 10), a bucket and a colander.

Tank size and temperature by source

Source	Tank for one betta	Water temperature
Illinois column	“ideally” 5 gal “or larger”	76-81°F
Tree of Life	“Minimum 5 gallons for a single betta”	78-80°F; “Avoid temperatures below 76°F (24°C), which can weaken the immune system.”
PetMD	“At least 2.5 gallons; 5–10 gallons is ideal”	76-81°F
Aqueon care guide	No figure: “they don’t require a lot of space. However, larger habitats are more stable and easier to maintain.”	76-85°F
Aqueon setup article	No figure: “plenty of space to swim”	“about 76 to 81°”

PetMD’s text also calls “10 gallons or larger” ideal, and its FAQ says “A 2.5+ gallon aquarium with a lid is ideal”. Our betta tank size guide compares the size figures, and our 5-gallon guide covers that size.

Safety

Fluval, a filter maker, says in its AquaClear manual: “Always unplug or disconnect all appliances in the aquarium from electricity supply before placing hands in water, before putting on or taking off parts and while the equipment is being installed, maintained or handled.” Also: “If the appliance falls into the water DO NOT reach for it! First unplug it and then retrieve it.” And: “If the plug or receptacle does get wet, DO NOT unplug the cord. Disconnect the fuse or circuit breaker that supplies power to the appliance. Then unplug and examine for presence of water in the receptacle.”

Setting up the betta tank, step by step

Nothing is plugged in until step 5.

Place the tank and rinse the gravel

Aqueon: “Rinse gravel with tap water using a colander, wire strainer or fish net. Do not use bleach, soap or other cleaning products.” Some planted soils say not to rinse (ADA’s Amazonia does); follow your bag.

Choose fin-safe decor and place it

Aqueon’s betta article: “steer clear of artificial or live plants with sharp or pointy edges that can tear your betta’s fins.” PetMD: “Avoid sharp decorations, rusty metal, painted ornaments that can flake, and items like shells/coral/sand collected from beaches that can alter pH.” Dr. Keller: “Decorations for a tank should never take up too much of the tank, pushing the fish to the periphery”. Aqueon places decor at the half fill (step 4): “Install artificial plants, rockwork, driftwood and other decorations at this time. Live plants and fish, should not be added until the aquarium has been running for at least 48 hours.” To plant later, follow the hands-in rule in step 8.

Fit the filter and heater, still unplugged

Aqueon: “Do not plug the heater in yet.” Hydor, a heater maker, in its Theo manual: “Always ensure the water level stays above the ‘Minimum water level’ mark shown on the heater”.

Fill with conditioned water

Aqueon’s betta guide: “Always treat tap water with Aqueon BettaBowl Plus or Water Conditioner before adding it to the aquarium.” Aqueon’s set-up guide fills about halfway, adds the decor, then fills to 1 inch below the rim before the filter starts.

Prime the filter if it needs it, and plug it in

Aqueon: “Prime the filter and plug it in using a drip loop. A drip loop is when you allow the cord to drop below the outlet before it rises up to plug in.” Fluval: “Do not allow filter pump to run dry.”

Plug in the heater after its wait, then check the thermometer

Hydor’s Theo manual: “Do not connect the heater to the power supply when it is not submerged in water.” Waits differ: Aqueon’s setup article, once the tank is full and the filter running, “After 10 minutes, plug the heater in.”; Fluval’s E heater manual, “Allow heater to acclimatize in the aquarium water temperature for 20 minutes before plugging it into the electrical outlet. Be sure to arrange a drip loop for the heater cord and any other electrical item that is placed in or on the aquarium.”; Hydor’s Theo manual, “wait a few minutes before switching it on”; Aqueon’s Pro heater manual, “a minimum of 30 minutes prior to powering” (quoted in our heater roundup). Your heater’s manual comes first; with none, our reading is to wait at least 30 minutes, the longest quoted here. Makers differ on setting it: Aqueon’s setup guide sets a dial before the heater goes in, and its Pro manual says to let it run 24 hours at its original setting before adjusting. Follow your manual; our tank temperature guide covers checking it. To adjust it with your hands in the water, unplug all appliances first, then prime the filter if it needs it and plug everything back in, the heater only while fully under water.

Fit the lid and give the light a day-night cycle

Aqueon says betta fish “prefer day-night cycles just like you do, so turn off the lights at night.”

Cycle the tank

PetMD: “While there are options to cycle without fish, often best results are obtained by cycling with fish in the tank.” It adds: “If you utilize bacteria starter cultures, you can significantly reduce the stress on the fish during this period.” It says cycling “can take four to six weeks, and water should be tested during the cycling period.” The sources above describe two ways; on a fish-in cycle the betta goes in first (step 9 before step 8, our reading); our cycling guide sets out both. Each time your hands go in (to test, change water, add live plants or move decor), unplug all appliances first. Before a water change, the heater needs its wait: “at least 5 minutes” (Hydor’s Theo manual) or at least 30 (Hydor’s support page; Fluval’s E manual); with no manual, our reading is at least 30 minutes. Afterwards, restart the filter (Fluval: “Follow operating instructions to restart and prime power filter.”) and plug everything back in, the heater only “when the Aquarium is full and the heater is completely submerged” (Hydor). Our betta tank cleaning guide covers water changes.

Float-acclimate the betta when it goes in

Unplug all appliances before your hands go in; once they are out, prime the filter if it needs it and plug everything back in, the heater only while fully under water. Aqueon: “It is recommended to use the floating acclimation method. Be sure to discard any water from the bag and not add it to the aquarium.” Our guide to adding new fish gives float times.

Feed in the amounts sources give

Sources differ on the minutes. Tree of Life: “Feed once or twice daily, offering only what they can consume in 1–2 minutes.” The Illinois column: daily, “the amount of food it can eat within 3 to 5 minutes, without any food left over”. Our betta food roundup compares foods.

Common mistakes

Mistake	What to do
A bowl instead of a tank	Dr. Keller: “They should not live in bowls.”
Untreated tap water	Aqueon: “First, don’t pour tap water into your aquarium.”
Betta looks unwell	Test the water and contact an aquatic veterinarian

Ready to buy?

Our betta tank roundup compares eight kits, and our Tank Setup & Care section has more set-up guides.

Frequently Asked Questions

Q. How long should you wait before putting a betta in a new tank?

Aqueon’s betta guide, on setting up: “Set the container up at least 48 hours before purchasing your new betta.” PetMD, on cycling: it “can take four to six weeks” (step 8 gives its fish-in preference).

Q. How do you prepare water for betta fish?

Dr. Keller: “If tap water is used in the tank, it is recommended to use a dechlorinating product and test for heavy metals”. On distilled water sources differ: the Illinois column says “distilled water should not be used as it lacks vital minerals that are important for fish health”; Aqueon’s setup article says to distilled or tap water “add a betta water conditioner to restore essential minerals”, and calls “Deionized water” ideal.

Q. What do you put in the bottom of a betta tank?

PetMD calls substrate optional and names “Live plants, driftwood, and smooth inert decorative rock” as ideal.

Q. Can two bettas share a tank?

The Illinois column says bettas “should not be housed with any other betta fish because they will fight and injure each other, often resulting in death.” Our betta tank mates guide covers other species.

Sources (12)

Aquarium Tales Team

Written and reviewed by the Aquarium Tales Team. See the About page for how we work.