Changing Light Spectrum

would changing the from a mh to an hps weekly have any positive or negative effects? my plants are two weeks into flowering.

are you asking, one week MH and one hps?

I would think this would be a pane in the ass for you and would stress the plants out, kind of like spending a week in July then one week in October.

flowering plants need red spectrum more. Dont use a mh during flower only. It wont do you any good. Adding both at once could help you out but only mh and no hps isn't going to help your plants. This will only end in less yielding stretchier plants.