How do you use Sensi Grow Part A&B in soil? And more.

I just bought Sensi Grow Part A&B and im like 3 weeks in. The plants are not very big.

http://img301.imageshack.us/img301/3...0144zs3.th.jpg

I took that picture a few days ago so they are a bit bigger.

I have two questions.

Question #1. I have a 1 gallon container that i use to water my plants. How much of each part A and part B do i add to water?

Question #2. My plants are not very big, thus most of the soil in the pot is "root free". If there are no roots to soak up the nutrients, will the nutrients build up and later, once my plants roots grow more, put my plant into nutrient lock?

Thank you very much.
These are the instructions sensi grow gave me. Sensi Grow (Part A & B)