The tall one is under 6 four foot 32 watt T8 light bulbs. The other is under 3 of those.
In fact they were there all summer.....I never got them outside this year
I prefer putting them outside when it gets warm enough. I just never got around to it this year (its been a crazy summer). They seem to have done well despite that I am happy to say.
Yes they are the easiest trees to keep inside that I have come across so far.