I recently switched from 4-4 foot florescents to a 400 watt high pressure sodium. My plants were real healthy and thriving before i switched lighting. The plants are 9 weeks and starting to flower. Now in the new light the plants are starting to sag all the sudden. Im realy familier with propr watering and i know thats not the problem. Temperature is ok. Around 80. Please help. I just went from 24 7 with the florecents to 18 and 6 with the hps. In a weeks im planning on going to 12 and 12. Please give advise. I have never grown with hps.