(PLEASE HELP) Is this stretch or just normal growth?

Ok, so I've got these two white widow seedlings. I just moved them from a grow box to an indoor closet yesterday and they were about 1". I came to check them 24 hrs later and it looks like they've stretched to 2 1/2"-3" overnight. They were started out under the same 150 w sunsystem hps lamp that they're under now, currently 11" away from the top of the plants.

My question is, is this stretch caused by light deficiency? If so, how if I've got a 150 watt hps RIGHT THERE..

And if it's not, then what's going on. I've got them on a 20-4 light cycle. Fox farm soil, Fox farm grow big. Please help.

Sorry forgot the pics

next time start them in a rapid rooter to promote root division. they are fine but i would keep the light atleast 18inchs, they dont need much to grow and a little stretch is ok. good luck

Thanks. Ill monitor for the next few days. And next time try rapid rooters.