Welches Stadium wieviel Licht?

i will say this with certainty... they will quikcly need more after initial sprout... don't let them "stretch" ... but also make certain some internode does develop. a bunch of leaves all popping out from same location is a good sign of too much light. (normal nodes tightly packed ... there are genetic abnormalities that cause such things - like 3 leaves from a node or a polyploid plant, which obviously has nothign to do with light.)

it will vary by plant, though most will be similar... take some notes andn eventually you'll just do it by feel. how the plant grows is your best guide... if you focus on what is observable and measurable, you can react to each plant appropriately. Distance between growth nodes is called an internode. How much it stretches / lengnthens is your guide to how much light to provide... too much length, you increase light. too short of a distance, you reduce light. Do that and your plant will grow robust and strong. You may err on either side a few times before you recognize it better. it's just a matter of time and familiarity.