Is it Enough?

Hello there, I have a question...I have five plants, which are about 2 weeks old, only two sets of leaves each. I own two 220W HPS, but currently have them under one of them, instead of the two. Is that okay, or would it be more benefitial to have them both on? If not, how long should I wait? They are currently under 24hs light.

I want to put them into flowering as early as I can (I cannot wait to smoke), when do I know it's time? Oh, as a side note, some are showing yellowish tips in leaves, and some white spots, I really don't know why. It's definitely not overwatering. The earth that I bought I think it's not the best, Ill be looking to transplant them, I hope it doesn't stress them too much. Ill be posting some pictures later.

Not sure about the plant problems but I know that more light is usually better if you can keep them enough space away to not burn them. On the flip side of that you can also grow effectively with CFLs, so technically you can do it with less than a HPS bulb.