Switching from MH to HPS

I have been flowering my four plants under two 175 watt metal halides on a timer controlled 18/6 light cycle for five weeks. My 400 watt hps just arrived. I am about to switch to the hps and a 12/12 light cycle. Is there any special methods for doing this conversion, or is a sudden change of light ok? Also, would it be beneficial to leave one of the 175 watt metal halides throughout the flower stage?

yes you just change from one to the other, but i wood have both runing at the same time,

i think the 400w alone will be fine.

Thanks for the advice. This is my first grow. Do these plants look like they are capable of having a decent yield with a 400 watt hps if every thing else goes as planned?

ive heard MH produce a better yield than HPS... but then again that might just have been the strand difference.

Under a 400w, with those four plants you should get a decent yield. Anywhere from 3oz to 6oz would be my guess, granted they're all ladies.

For switching the light, just do it right before the lights come on, or right after, but be quick about it. Maybe have a green lightbulb in place so you can see(plants don't see green spectrums, so they'll think they're still in the dark).

I might recommend having one of your MH's running with the HPS if it's possible. I promise you're plants will love it.

P.S.-
MH spectrum is used for a plant to get better foliage and a better established root system(helps make squatter plants as well).

HPS spectrum focuses mainly on bud development.

This is why you use MH for veg, and HPS for flower. However, the combination helps immensly throughout. Maybe 2 MH-1 HPS fer veg, and 2 HPS-1 MH fer flower.

lol, yea, but I assumed he just meant grown under when I read his light regime.