How Much Light Do Indoors Seedlings Need?

A good starting point is providing around 15-20 watts per square foot of growing area for the seedlings. So if you have a 2x2 ft grow area, you'd want a grow light in the 60-80 watt range positioned above it.

As the seedlings develop their first set of true leaves after the initial cotyledon leaves, you can gradually increase the light intensity up to around 30-40 watts per square foot. Alternatively you can adjust the hanging height to control the light brightness.