is it a big problem to switch from MH to CFL for my mothers?

growing 2 mother plants from seed right now with a 400 watt Metal Halide bulb bout 30,000 lumens give or take and after i get em to a desired size im gonna need the light system to flower so i plan to switch the mothers to a double 40watt flourescent light with a cool white n a soft white bulb,i expect them to slow down growth speed rate relatively but would they slow down on putting out cuttings dramatically? or have any other problems?

& ill probably throw in a couple other little flourescents i have layin around

Changes in lighting present only a mild stress. They will adapt fairly quick.