400 to 1000w light

I have veg and just started week two of flowering. Want to change the light to 1000w. good or bad idea. I let them veg for like two extra weeks so the plants are oversized

Depends on room size. I am in a 5x5x7 and I have 2~ 600hps for bloom. If I where in a 4x4 I would go with 1~1k And when I was in a 3'8" x 3'8" I had 1~600hps and 4 plants under it. My harvests came in at 20-23oz every time. Like you I veg hard.