Where are you looking at getting those nutrients? I haven't seen anywhere that the shipping is that high. I found my local hydro store on maps.google.com and just searched Hydroponics near my ZIP code.

Anyways, what I did was I had the rockwool cubes surrounded by hydroton in my E&F system and put the germinated seeds right in there. Its been 5 days and they are doing pretty good, but may have stretched a tad due to my light placement. Basically, you can put them in whenever you feel like it.

Also, it would be better to veg under something other than HPS, such as MH or CFLs because of the spectrum, but it won't be detrimental to your grow. Just make sure the light isn't too close or the plants will burn. Good luck! :thumbsup: