New HPS light?

I just setup my new grow room, with mylar, 400w HPS, and vents but currently I have my seedlings (2 weeks old) under flourescents and they are really thriving. Should I switch it to the HPS or just ride the flourescents out to about 4 weeks?

I just don't want to mess up something that's working fine.

Depends on what you want to accomplish, saving a little money on electric or growing bud. I would introduce the 400 watt at about 2' above the plants and then move it down a few inches a day as the plants grow up until the light and plants are about 8" apart. Your plants will be ready for you to take clones from them at least two weeks sooner assuming everything else is done right. VV

What kind of flourescents? If they arent stretching, and are looking good. Then why would you switch?

Im with victor, I would say wait till they get a bit bigger, and need a more penatrable light source, such a hps. When they are small, flouros can do the job, becuase there isnt as much plant to cover.