Ciujbauanswered grow question 3 years ago I've got a Mars TSW2000 for flowering cycle - 50CM from canopy at 100% .
As others said , they can take full power from start , but just adjust the height of lamp .
1m from seedlings could make them stretch in veg as they try to reach for light (that's what I saw on my grow ) - I've had 100% at 70-80CM from seedlings and got good results .
Not using TSW2000 for veg anymore - having a 2nd tent for veg - but using a TS1000 at 100% and 55CM from canopy and I've got no issues so far (except some nute imbalance and/or overwatering)