Confused on nutrient amounts outdoors

Hey there. I'm looking for insight on my upcoming feeding routine. First let me explain my setup..

I am attempting my first outdoor grow this season.I have 17 seedlings close to 4 weeks old that are still in 16 oz cups. Hoping to transplant them in a week or 2 at the most. Made 4 plots that consist of Pro-mix BX, coir, perlite, and some of the native earth. Went out today and bought a 7lb bag of Foxfarm Marine cuisine and a bottle of Foxfarm Grow Big. These 2 things are what I hope to provide nourishment to the plants.

Let me know if this sounds alright.. I plan to take the Marine Cuisine out to the plots and try and have it established before taking the plants out there. How should I do this? The packaging says to use 1 tbsp per gallon of soil and to mix it 6-8" into the soil.. I'm not sure how much soil I have, so I'm clueless as to how to do this correctly. THe majority of my soil is from a 50lb promix BX bail. No idea how many gallons that is.... Is there an easier way to do this correctly? Can I just cover the garden with Marine Cuisine in a light coating and then mix it in???

Also, when I bought the Grow Big I bought the hydroponic version. When I realized there were 2 versions, I took it back and was told that ppl use the hydroponic one for dirt as well... so I kept it. But again, the instructions say to use 3 teaspoons per gallon. I assume since its a hydroponic formula that they are implying 3 teaspoons per gallon of water.. Is this right? How much Grow Big should I be using?

I'm Cdn, and all this talk of gallons for measuring everything is throwing me off

Thanks.


edit: I should add that I been using 2 5 gal. buckets out at my grow location for various things and I think I'll clean them out well and use them to carry water for my plants. So, I guess I'll be mixing ferts into close to 5 gallons of water most of the time. Not sure if that helps with the math. I just read that a 3.8 cubic foot bale of BX is equal to 7 cubic feet when it fluffs up. and 7 cubic feet is equal to 45 dry gallons.

**So, should i be using roughly 45 tablespoons of marine cuisine for my grow?? And should I then be putting 3 teaspoons/gallon of water when I feed the Grow big, being 15 teaspoons per 5 gallon bucket of water??? I have a feeling I have this horribly wrong.. this seems like way too much

anyone? Can anyone at least confirm if I've got the amounts right or if I am horribly incorrect? I'm hoping to go out tomorrow and put the marine cuisine in. I certainly don't want to over do it. If I don't get a response I suppose I'll just be cautious and use less rather than more. Since it's time release and all, I'd like to get it all set up a week+ before the plants go in. Just makes it easier and quicker on transplant day. I think my Pro-mix BX 50 lb bale with the 2 bags of perlite and 3 coir bricks would make up roughly 50 gallons of grow medium total. So, if I understand correctly I would want to mix roughly 50 tablespoons of marine cuisine into the top 6-8" of my soil. Thanks.

/bump

Don't mean to be rude with the "bumps" but I'm really wanting someone with knowledge in this area to respond before tomorrow morning since that's when I plan to head out and do the last bit of prep of my plots before I transplant next weekend.