Tank Setup

Betta Gillfriend care rules: one betta per tank. Mirror or flare practice: one 2-minute session a day, with at least 2 rest days a week. Train: up to 10 minutes a week.

A good setup does most of the work of keeping a betta healthy. The goals are simple: stable warm water, clean water, gentle flow, a lid, an air gap, and plenty of soft cover. Set the tank up and cycle it before your betta comes home.

Quick checklist

Tank of at least 5 US gallons (about 19 L); 10 gallons (about 38 L) or more is even better, and recommended for giants
Lid or cover, with an air gap above the water
Adjustable submersible heater
Thermometer you can read at a glance
Gentle filter (sponge filter or a filter with adjustable flow)
Water conditioner that treats chlorine and chloramine
Liquid test kit for ammonia, nitrite, nitrate and pH
Smooth substrate, live or silk plants, at least one hide, and a resting spot near the surface
Light on a timer
A dedicated bucket, siphon and net used only for fish

Tank size

What the evidence says

Source	What it found or recommends
Oldfield and Murphy (2024), Animal Welfare	Males swam much less in 0.5 L bowls than in larger tanks. At least 10 L allowed the full expression of swimming behaviour, and enrichment (gravel, rocks, plants) increased swimming.
"Life beyond a jar" (2024), Animal Welfare	Males tested in 1.5, 3.3, 5.6 and 19.3 L tanks were most active and showed the fewest abnormal behaviours (hovering, pacing) in the furnished 19.3 L tank. A bare tank of the same size caused more abnormal behaviour. The authors recommend tanks larger than 5.6 L at home, always with gravel, plants and refuges.
RSPCA Australia	Ideally 20 L or more, with 10 L as the absolute minimum.
Dr Krista Keller, University of Illinois vet hospital	Bettas should not live in bowls; ideally a 5-gallon tank or larger.
PetMD (vet-written)	At least 2.5 gallons; 5–10 gallons is ideal, because bigger tanks hold temperature and water chemistry more steadily.

Tip: You may read (for example in a UF/IFAS fact sheet) that bettas can thrive in small containers when water is managed very carefully, as on commercial farms. That is true for survival and growth, but the newer welfare studies show bettas behave more naturally with more space and furnishings. Because welfare is our priority, Betta Gillfriend recommends at least 5 gallons (about 19 L), furnished, as the baseline.

Welfare: The little cups and bowls bettas are often sold in are for the trip home only, never a home. Your betta will thank you for at least 5 gallons (about 19 L), a heater set to 76–81°F (about 24–27°C), a gentle filter, a lid and cycled water.

Why bigger is easier

More water dilutes waste, so ammonia and nitrite build up more slowly.
Temperature swings less.
There is room for plants, hides and exploring, which the welfare studies show matters.
Tanks that are longer than they are deep suit bettas, which naturally live in shallow water. (The "Life beyond a jar" authors suggest this too, though they did not test depth directly.)

Extra notes for giant bettas

Giant plakats like Rip are much larger than standard bettas. A genetics study describes giants as about three times larger than the wild type, and the IBC standard expects a giant male body (not counting the tail) to be at least 6 cm long.

Go bigger: we recommend 10 gallons (about 38 L) or more for a giant. This is our guidance, scaled up from the evidence for normal-sized bettas; no study has tested tank sizes for giants specifically.
More waste: a bigger fish eats more and produces more ammonia, so test water more often and keep up with water changes.
Bigger hides: make sure caves and gaps are large enough that a giant cannot get stuck. Choose hides with wide openings.
Sturdy lid: giants are strong swimmers and jumpers.
Feeding: a giant needs more food than a standard betta, but overfeeding is still a risk (see Diet and feeding).

Heater and temperature

Bettas are tropical fish. Most homes are too cold for them, and room temperature also swings between day and night.

Item	Our recommendation
Target range	76–81°F (about 24–27°C)
Day-to-day goal	Keep it steady. Stability matters more than hitting one exact number.
Heater	Adjustable, submersible aquarium heater. PetMD suggests about 3–5 watts per gallon.
Thermometer	Always. Check it daily. Do not trust the heater's dial alone.

The University of Illinois vet hospital and PetMD both give 76–81°F. RSPCA Australia gives 24–26°C, which sits inside that range.
Many vet and research sources note that bettas do well towards the warmer end. A research colony keeps its bettas at 28°C (82°F) for breeding work.
Merck Veterinary Manual notes that temperatures outside a fish's natural range suppress its immune response. As a general rule it suggests changing temperature by no more than about 1°C (or 1°F) per hour.

Warning: Lamps above small bowls are not a safe heat source. They are often switched off at night and can under- or overheat the water. A submersible heater is the reliable option.

Tip: Use a heater guard or place the heater where your betta cannot rest against it, and unplug the heater for a few minutes before taking it out of the water during water changes (follow your heater's own instructions).

Gentle filtration

Wild bettas live in still or slow-moving water (see Meet the betta), and heavy-finned domestic bettas are weak swimmers, so they need calm water.
But filtration still matters: the filter is home to the "good bacteria" that break down ammonia (see the nitrogen cycle below).
Good choices: an air-driven sponge filter, a box filter, or any small filter with adjustable or low flow (PetMD).
The Illinois vet hospital notes that low-flow filters also protect delicate fins from being sucked against the intake.

Tip: If your betta is being pushed around, struggling to swim, or always hiding in one corner away from the outflow, the flow is too strong. Turn it down, aim the outflow at the glass, or baffle it with a sponge or plants. A pre-filter sponge over the intake protects fins.

RSPCA Australia advises adding an air stone if the filter does not stir the surface at all, so the water stays oxygenated.
Clean filter media gently, in a bucket of old tank water, never under tap water. Chlorine can kill the beneficial bacteria (RSPCA).

Lids and jumping

Bettas are good jumpers. Always use a lid or cover (RSPCA Australia, PetMD).
Leave an air gap between the water and the lid. Bettas breathe air from the surface, and warm, humid air above the water is good for them.
Cover any gaps around filter and heater cords too.

Lighting

Keep the tank out of direct sunlight to avoid algae and overheating.
RSPCA Australia recommends aquarium lights on for no more than about 10 hours a day, and at least 8 hours of darkness each night, with nearby room lights off too.
A simple timer keeps the day/night rhythm consistent.
Live plants need enough light to grow, so choose a light suited to your plants.

Plants: live vs silk vs plastic

Type	Pros	Cons
Live plants	Use up ammonia and nitrate; natural cover; the welfare studies used live plants	Need suitable light; can carry snails or pests; buy from aquarium stores only
Silk plants	Soft, safe for long fins, no care needed	No water-quality benefit; need cleaning
Plastic plants	Cheap, durable	Edges and tips can be hard or sharp and may tear fins, especially on long-finned males

RSPCA Australia advises that decorations and plants should not have rough edges, as male fish with long fins are especially prone to fin tears. It also advises buying plants and plastic decor only from aquarium stores, and never collecting plants from the wild.
The Illinois vet hospital warns that many decorations have sharp edges that tear fins, and that decorations should never take up so much space that the fish is pushed to the edges.
A research colony notes that live plants reduce ammonia and nitrite in grow-out tanks.

Tip: A simple fin-safety test: gently run a pair of thin tights (pantyhose) or a soft tissue over decorations. If it snags, it can snag fins too. Sand down rough spots or swap the item out.

Beginner-friendly live plants often used with bettas include anubias and java fern (attached to wood or rock rather than buried), floating plants, and broad-leaved stem plants. Ask your local aquarium store what grows well under your light.

Hides and resting spots

The welfare studies found bettas spend a lot of time resting on or against furnishings, and that barren tanks led to more abnormal behaviour. Give choices: at least one cave or hide and several plant thickets.
RSPCA Australia suggests tall plants with large leaves where bettas can rest close to the surface at night. A "betta leaf hammock" does the same job.
RSPCA Australia also suggests having one covered side so the fish is not exposed to bare glass on every side.
Use smooth gravel, sand, or pebbles. The furnished tanks in the welfare study had gravel.

Leaf litter and Indian almond leaves

Dried Terminalia catappa leaves (Indian almond leaves) are widely used by betta keepers. They release tannins that tint the water tea-coloured, a bit like wild blackwater.
Some small studies on bettas found leaf extracts associated with better survival and blood values, and one found improved resistance to a bacterial challenge. These are small studies, mostly from farms and labs, so treat leaves as a nice optional extra, not a medicine.
Leaves can lower pH, especially in soft water or at high amounts. In one study the highest dose dropped pH to about 5. Start with a small piece, and test pH.
Remove leaves once they fall apart, or let them break down slowly as natural leaf litter and siphon the bits during water changes.

The nitrogen cycle

Fish produce ammonia, through their gills and in waste. Uneaten food also rots into ammonia. In a healthy tank, two groups of beneficial bacteria living mostly in the filter and on surfaces process it:

Ammonia (NH₃/NH₄⁺): toxic. Bacteria convert it to...
Nitrite (NO₂⁻): also toxic. It damages the blood's ability to carry oxygen. Other bacteria convert it to...
Nitrate (NO₃⁻): much less toxic, but it builds up over time. Water changes and live plants remove it.

A new tank has almost none of these bacteria. Setting up a tank and adding a fish straight away often causes "new tank syndrome": ammonia and then nitrite rise to harmful levels over the first weeks. Merck Veterinary Manual notes that a new biofilter can take up to about 8 weeks to establish. Commercial bacteria starters can speed this up.

Warning: Antibiotics and some other medications can harm the beneficial bacteria. This is one reason we treat sick fish in a separate hospital tank whenever possible (see Common illnesses).

Fishless cycling, step by step

Fishless cycling grows the bacteria before your betta arrives, using bottled ammonia instead of a living fish. Merck Veterinary Manual describes it as a way to avoid new tank syndrome. The steps below follow the method described by Dr Tim Hovanec (DrTim's Aquatics) and Merck.

You will need: pure ammonia or ammonium chloride made for fishless cycling (never household ammonia with soap, scent or other additives), an ammonia test, a nitrite test, a nitrate test, and optionally a bottled nitrifying bacteria product.

Set everything up. Fill the tank with dechlorinated water. Run the filter and heater (warm water helps the bacteria grow). Add substrate and decor.
Dose ammonia. Add enough to reach about 2–3 ppm (mg/L) ammonia. Do not go above 5 ppm. Write down how much you added. If you are using a bottled bacteria product, add it now, following its label.
Test every 2–3 days for ammonia and nitrite. Keep a simple log, or use the app's notes.
When nitrite first appears, the first group of bacteria is working. Add a top-up dose of ammonia (Dr Tim suggests about half the starting amount).
Keep feeding the bacteria small doses of ammonia every few days as ammonia drops. Watch nitrite: keep nitrite below 5 ppm, because very high nitrite slows the bacteria down. If ammonia or nitrite climbs too high, do a partial water change.
Watch for the nitrite drop. Nitrite often peaks a couple of weeks in, then falls quickly as the second group of bacteria grows. Nitrate will rise.
Test for "cycled". The tank is ready when you can add a full dose of ammonia (2–3 ppm) and within 24 hours both ammonia and nitrite read 0, with nitrate showing.
Do a big water change (dechlorinated, temperature-matched) to bring nitrate down before adding your betta.
Add your betta and keep testing for the first few weeks. Feed lightly at first.

Troubleshooting

Problem	Likely cause	What to do
Cycle "stalls"; ammonia or nitrite stops dropping	pH has fallen too low (often below 7). The bacteria make acid as they work.	A 20–25% water change usually restarts it (Dr Tim).
Ammonia or nitrite very high	Too much ammonia dosed	Partial water change to bring both under 5 ppm
Cloudy water	Bacterial bloom from decaying material	Usually clears by itself
Still not cycled after 6–8 weeks	Low pH or low alkalinity, chemicals in the tank, too little ammonia	Test pH and KH (alkalinity). Low alkalinity lets pH crash, which stalls the bacteria.

Tip: Running out of time? You can seed a new filter with media from a healthy, established, disease-free tank, or run the new sponge filter in that tank for a while first (Merck describes this for quarantine tanks). Never take media from a tank that has had recent illness.

Warning: Do not add ammonia-removing products while fishless cycling. They complicate the process (Dr Tim).

Cycling with a fish already in the tank

If you already have a betta in an uncycled tank, don't panic. Test ammonia and nitrite daily, feed lightly, and do partial water changes whenever ammonia or nitrite is detectable. Merck recommends a large water change (50% or more) when ammonia is high. A bottled bacteria product, and a dechlorinator that also binds ammonia, can help in the meantime.

Sources

Care guide by Betta Gillfriend (Bespok Labs, BC, Canada). It is general information, not vet advice. If your betta is sick, ask an aquatic vet.