Starting flowering under t8 then to 600w hps?

i have about 10 plants in 2 ebb and flow trays, under 4x36w t8 lights, 2x4000k and 2x5000k, there about 2 months old i think.
i also have 5 plants at 7 weeks flowering under a 600w hps. was wandering if i could start flowering the plants under the t8's for 2 weeks or so till i harvest the other batch? or should i be saving there growth spert for the hps and not the t8's?
heres some pics...

View attachment 1799228

???????????? or should i just wait and start flowering them under the hps?????????????

wait man the stretch is gonna be shitty under the t8s and reduce your yield.