Harlequin Rasbora Temperature: Ideal Water Temp
Ideal: 73-82°F (23-28°C)
The Harlequin Rasbora is a tropical species. Aim for the middle of its range, around 78°F, and keep it steady — sudden swings stress fish more than a stable temperature.
You will need a heater to hold 73°F and up in most rooms — use roughly 3-5 watts per gallon plus a separate thermometer.
| Fahrenheit | 73-82°F |
|---|---|
| Celsius | 23-28°C |
| Sweet spot | ~78°F |
Frequently asked questions
What temperature do Harlequin Rasbora like?
73-82°F (23-28°C), ideally around 78°F.
Does a Harlequin Rasbora need a heater?
Yes — to reliably hold 73°F+ you need a heater in most homes.
More on this species: Harlequin Rasbora full care guide · tank size · temperature · pH & hardness · tank mates