tackytony

My first grow. Growing in 3.5 gal buckets with soilless "Sunshine Mix". I have 3 400W HPS in a 4 x 10 area. I germinated from seeds and am about 1.5 weeks into flowering. Things are going fairly well, with one exception:

What do I do if I think some of my girls are going to be too tall for the room before harvest? At only 1.5 weeks into harvest, there is only about 1 foot of growth room on several of the plants, and they are already about 5 feet tall now! I expect they are going to get much bigger (or will want to get bigger), but I don't have any more ceiling height left. I'm already getting flowers so am not sure if I will be chopping my own head off if I "top" the plants down and let the remaining branches continue to bloom at a lower height.

What is the best way to approach this problem? (I grant you it's a good problem to have, but a problem all the same)

Thanks!