That is only enough light for some seedlings. You cannot mature a plant with that light. You will need more. 1600Lumen just isn't quite enough.

It will get your seedlings started, providing it's the right spectrum. But you will definitly need more light and both ends of the spectrum. You did read the section on the forums here about light spectrums and what not, correct?

White seeds are no good usually, as stated by Reaper. Sometimes those little black ones are no good as well though. Sometimes they can be "overmature" which means they are probably dried up inside.

The best seeds you can find are striped, slightly dotted, or brown and black seeds. This means they are fully mature and ready to go. Size really means nothing as far as I know.

Tip - When you buy a sack and find some seeds, put them in some sort of real small air-tight jar or vile. Then place them in the freezer. Only remove this storage decive from the freezer when you plan on removing seeds to grow with. Once you have placed the seeds in the freezer you MUST keep it in the freezer or the seeds will be compromised...