Betta Fish Dashboard

Cheatsheet and Calculators for Betta fish tanks.

Weekly Water Change

Tank size (gallons)

Tip: include only the filled water volume, not substrate or decor displacement.

Change percent per week

Common range 20 to 35 depending on stocking and nitrate rise.

You should replace

2.5 gal (9.46 L)

Condition fresh water and match temperature before adding.

Parameter	Target range	Notes
pH	6.5 to 7.5	Stability beats perfection. Avoid rapid shifts.
Ammonia (NH3/NH4+)	0 ppm	Any detectable ammonia is harmful.
Nitrite (NO2-)	0 ppm	Toxic even at low levels. Indicates cycle trouble.
Nitrate (NO3-)	< 20 ppm	Keep under 40 ppm at all times. Water changes control this.
Temperature	78 to 80 °F	Acceptable 76 to 82 °F. Use a heater and thermometer.
GH	3 to 12 dGH	Soft to moderately hard is fine.
KH	3 to 8 dKH	Provides pH stability. Very high KH locks pH alkaline.

Carbonate hardness in ppm (mg/L as CaCO3)Carbonate hardness in dKH

1 dKH = 17.9 ppm.

General hardness in ppm (mg/L as CaCO3)General hardness in dGH

1 dGH = 17.9 ppm.

°F°C

Betta sweet spot: 78-80 °F (25.5-26.7 °C).