I'm also wondering the same thing.
I was planning to clip tops and give another 2 weeks for the lower sites. Based on what I've been reading, this can be done. It will stress the plant but in the end smaller sites can grow bigger. They get more light and more energy from the plant. Of course if the plant healthy enough to manage things. And feeding/watering must be balanced very carefully.
This can be a good option for fluorescent lighting :thumbsup:

or
Get an HPS system