Cannabis is still very fragile in the seedling stage so it is recommended to wait until the plant is at least 25-30cm tall before placing it under a full power growing lamp (when growing indoors). As soon as you see any green shoot crack from the seed casing and/or the seed sinks to the bottom of your glass of water, it should be placed under fluorescent cool white and warm white bulbs. This is typically from 3 days in darkness until 9-13 days at which point the seedling has reached the vegetative state
Keeping the seedling under a normal house lamp (or even just daylight) will give it a strong chance of building up a root base and a solid structure.
When growing outdoors it is recommended to start the process in a controlled environment before the season begins, therefore giving your plant the full opportunity to flourish once the season starts.