sexing clones under flours.

I have a veg room with flouresents and a flower room with 600HPS. Is is necessary to sex the clones under the HPS or can I build a small light tight container with a two foot flouresent and run it 12/12 to determine sex without running the HPS for weeks just to determine clones mother's sex? Or will not using the HPS cause the sexing process to take longer?

bump, i would like to hear more on this as well...

How about it? It sure would cost less to not use HPS/fans/etc.....

Someone has tried this before. I would rather not put the clones into the flower room until after verifying mother's sex. I have seen and read where growers put a clone of each mother into their flower room under HPS and in a few weeks are able to determine sex. I want to know if I must do it this way? Or can I use a small light tight area using floresents 12/12 for a few weeks too to accomplish the same thing without running my much more expensive flower room equipment?
Thanks for the input.

Still hoping for a response.