There is no perfect temperature for growing plants. Instead, temperature is a variable value that you can change during the cultivation of your plants. Each species of plant likes a different temperature.
The most important thing is to keep the temperature in your grow room from fluctuating too much. During hours of light stick to a temperature between 25°C-30°C, depending on your lamp’s light output.
During dark hours you can drop this to around 20°C. Make sure to keep the temperature difference between night and day as small as possible. Using differences in temperature you are actually re-enacting seasons.
If the difference between night and day is too large or the nights are too cold your plant will take too long to recover. There is also a larger chance that mildew will start forming. This is not beneficial for your yield.