I didn't know you were getting the master kush from gyspy. I doubt it is a tetra, or even a pure strain of master kush. If you are just looking for cheap seeds, he can't be beat. You might actually find something decent, but if you want something special...definitely not my first choice. Green Mojo.
I was talking with my son about the current grow and comparing it to the last grow. There a few things that will help increase THC and terpenes during the last 2 to 4 weeks of flowering. I have spoken of 1, about the temp difference of at least 10 degrees between lights on and lights off. Limiting total temp below 80, I have been using 78 with lights on and 68 with lights off. Another is decreasing humidity level to below 20% during the same time. The next is a bit harder. It's about stressing the plant, but not hurting it. THC and terpenes are defense mechanisms, so bring them out to the full extent of the genetics is to exploit that. My concern here is that this is a site where there are many beginner growers, and this is an advanced method that requires understanding what the plant is telling you. I typically do a LST and bend the tops of the plants. Some do a super cropping, some a massive defoliation of the plant, I know some who have driven a nail into the stalk and split it. These are all different types of stress to the plant...but in a controlled way and at a very specific time in the flowering portion of the grow. My son still doesn't quite get it.