I would hold off right now...not because the 1k would cause any problems with the plants themselves but because switching over from 400 to 1000 requires more than just the light and ballast themselves. More money has to be spent getting the grow space ready for the 1k. Fans, ducting, hood(sometimes), A/C all get more expensive and more needed to more light you run. Personally I went from cfls to 400 in one grow and did not notice and ill effects. If you want to totally redo your grow room, then go for it with the 1k, just don't expect it to be as easy as setting the light above the plants. I was shocked at what needed to be done when I set up a 1k. Good luck.