My kinda thread! First and foremost, you already have your lights nice and ready - have you done a dry run to test your temperatures? Run all of your lights on and see what the temperature hits, make sure it's not some crazy amount before you put all your plants in there. Don't run the high watt CFLs before your plant has at least two sets of leaves, not including cotyledons IMO. As well, I would keep them at a nice height the first 2-3 days so the plant can adjust to them.
What potting compost are you using? Do you know the name / brand / NPK rating of it? The home made kitchen waste compost is great, that's microbe breeding world.
You're running a system that's centered around organics pretty much with the compost so I'd get the GH line, it's not organic certified but it won't kill all your microbes either. Here's a link in the UK for them, you may be able to find them cheaper as I'm not familiar with UK hydro shops.
http://www.growell.co.uk/general-hydroponics-flora-nutrients.html
I'd get the grow, bloom and micro. That's 31 pounds or so.
As well, I'd get a pH pen now or when you can. There's one on that site for 40 pounds. That'd leave you with about 30 give or take. I'd get a microbe booster since you're running compost -
http://www.growell.co.uk/general-hydroponics-bio-boosters.html Bio Roots from GH would go well with the other nutes.
I haven't used GH but I've read countless threads, testimonials and praise for them. It's the cheapest most efficient nute you can get. It may not have EVERYTHING for the plant, but you definitely get your bang for the buck. There's an organic line, called General Organic which is a bit pricier and I can't seem to find it on the UK shops.
Welcome to AFN, please start a grow journal we'd appreciate it! Any help you need at all or any questions, post them up! Good luck with the grow and hope I was able to help.
