Will changing lamp from 250w to 400w stress my plants (in bloom)?

Hi! I'm growing 4 plants under a 250w HPS and they've been in bloom for 25 days. I just came over a 400w HPS (with ballast) and are just wondering if changing to it now will stress my plants and that i should wait till my next grow. Or is it ok to change it?

No it will not harm your plants those bitches will love it.
More light is your plants friend..

No it will not stress your plants.

They will thank you and grow bigger.