want to use 400 for first few weeks of flowering then switch to 600.. qs ?

hi all to save on some electric i wanted to use my 400w hps for the first few weeks of switching then use my 600w hps for the rest of flowering. my question is when is the ideal timeto switch to my 600 without sacrificing benefits of the 600?

I would only use the 400 for the first week or two after you go to 12/12. Once the buds start to show you want all the light you can get.

was thinking of just using the 400 for the first 3weeks until they stop stretching