First Grow Need Help

I have a closet grow, I'm using a 400 watt HPS and 6 pots. I'm using roughly 50/50 John Innes#2 Potting Compost and Perlite. A couple of weeks ago I germinated 6 seeds. 3 Afghan Kush Ryder, 1 Pineapple Express, 1 La Musa and 1 Biodiesel Mass. I put them all in glasses of water until they sunk and had broke the shell a tiny bit. They all done this in their own time, then i used the wet paper towel method. I checked them everyday and planted them as they became ready (something that i wasn't happy about doing but then changed my mind) One week ago I planted The Afghan Kush Ryder and the Pineapple Express. The Afghan Kush is doing well and looking green, but the Pineapple Express never sprouted. It just didnt work? Two days after i planted the first two I planted another Afghan Kush and the Biodiesel Mass. These two have now sprouted and are doing fine not nearly as big as the first Afghan Kush though. Today i have planted the La Musa (maybe a little early but I didnt want to wait anymore) and that leaves the last Afghan Kush germinating. This just hasnt seem to have germinated at all. It broke the shell a tiny bit after I'd put it in a glass off water but it hasnt progressed since. So I have 4 out of my 6 spaces filled. Im not sure wether to plant a couple of Himalaya Blue Diesels autos i have or a couple or regular Big Bud#2. I want as much herb as i can get for the summer so i would like a to fill all 6 spaces.



Thats my situation, here are my questions

What nutrients should i buy? I have all purpose miracle grow but i think its pretty basic stuff.
What fertilizer should i buy? I dont have any and was wondering if there is any natural fertilizer that can improve the yield or potency of my crop?
Should i lower my lights? Right now the light is about 30 inches above the top of my plant. I dont want my plans to be stretching but I am affraid that if i lower my light when my plants are so young it could kill them or stunt their growth.
What strains do you reccomend i grow next?
Any general advice, tips or suggestions?

Here are some pics of my set up





The Afghan Kush (the oldest)




This below is the Biodiesel Mass


This is the yonger Afghan Kush. Dramatic size difference compared to the older one for only being two days younger.

for nutes i'd get the fox farm trio its everthing u need. id lower tht light to 18in...good luck

thanks man il check it out, and lower the light