Chow_13answered grow question 2 years ago Dimming is not recommended unless your trying to save power. Especially if you have different led's on the same board. They will dim differently and can possibly change the spectrum. Go 90-100% all the time.
I would have the light at 30" above the canopy and adjust from there. If you notice the plant is stretching out( longer then 2-3" you should lower the light. If the "True" leaves are forming a V shape then its to close.
You want them to lay flat or be slightly angled up/down.
Once your seeds have broken out of your substrate REMOVE the humidity dome. Only reason to have it is so the substrate does not dry out during the first stages of root development.
Only water a little bit until they get bigger. Half a shot glass should be more then enough. Just because the top is dry does not mean the inside is dry. To much water will deprive oxygen from getting to the roots and cause issues.
Happy Growing