mh for flowering?

can i use a mh light for flowering?

sure why not!

An HPS would be be better for both veg and flower than MH. So if your debating which one to get go with the HPS.

use a MH Till they show sex then switch to the HPS for flowering.

I use 400w MH hole process it does me right.

you can definitely use MH throughout the entire growth cycle! It's best to switch to HPS at the 12/12 switch but using soley MH is much better than using just HPS so you're one level down from the best option. They'll take a little longer to flower than if you switched to HPS but you'll get a fine harvest