Soil

Hi all, Newb grower with a soil question. The strains are SLH and White domina. I'm an American stuck in Germany for a few years and decided to get my thumb a little green while here. My seeds have cracked and they have a nice beautiful taproot coming out so it's time for soil.
I bought a bag of Blumenerde (flower soil) but not sure if it's optimal or even ok for my newborns. Specs on the bag read: [N] 200mg/l [P2O5] 160mg/l [K2O] 950mg/l [Mg] 350mg/l 220mg/l and PH 6.5 [CaCl2]
From what I have read seems like I should have more N in veg but I was wondering if I can use this without starting my babies off on the wrong foot. Also should I maybe add more N (not sure how) or if thats unnecessary. I'll be using plastic beer party cups at first until about a week past their groundbreaking then put them into a bigger pot by carefully cutting the cup away and planting them soil and all into their new home and by then I'll be able to get better soil for the main pot filling.
This community is great and one of the main reasons I've made the decision to actually give it a shot instead of just dreaming about it. So thanks in advance for any advice and a big thanks for already giving me the grow bug. You guys rock.

Hmmmm. There's a lot of potassium in there, looks good for flowering. I would say just go for it with that soil until the plants have a few nodes on them, then you can supplement the soil with a high N fertiliser or feed (be careful not to over-do it though). My personal rule of thumb is if it grows tomatos it'll grow MJ, and I can't see why that wouldn't.

Never rely on information from just one person though it always pays to do a little research as well, just in case I've missed something substantial.

With the cups you're using, I suggest you punch holes not only on the bottom of them but also on the sides to help let air into the soil. It certainly seems to help with my clones - I turn the pots into colanders and let the soil hold the water.

Good luck!