when to put plants under hids?

how old do the babies (autos) need to be before putting them under a 1000 watt hps?

Ive got some that are about a week old, about 3 inches tall.

I had them in 16 oz styrofoam cups and just repotted all of them into 2 gal pots because they started looking a little sickly. now i dont have enough room to put them back under the flouros, and i think they might be too small to put under the 1000 watt hps.

I think they started looking sickly cause the flouros i have arent all that bright. Not near as bright as a cfl. So im on my way to the grow shop now to buy a hydrofarm t5 4ft 8 bulb setup that will run me qbout 260$ but im sure it will be alot brighter than the flouros im using now and i wont even have to put them under hids yet.
Id still like to know when is the soonest recommended though so i can get them in there asap.

Thanks

i guess i shoulda posted this in the noob section lol... well i just got back and got a 4' 8 bulb t5 setup so all should be good. ill just veg under them for atleast another week

Whenever you want them to start growing faster. lower the light gradually over 48 hours.