Quote Originally Posted by bigtopsfinn
Wait until it's about 5 nodes
I take that back... with an 18w light (75w equivalent?) it will take a while for that to reach 5 nodes, and it will stretch a lot. I put mine under a 400w hps after about 2-3 nodes. I started out with the light very high up and slowly brought it closer. Granted, this is a major waste of electricity using such a powerful light for one tiny plant.

Read up on lumens... aim for 5000 lumens per square foot at all times.