Here's the problem:
It's your first grow and you are using a complicated and unconventional feeding regimen, that no one in here is familiar enough with to give you a confident answer.
I'd say what others have said, which is that your plants probably need nitrogen. For your next grow, pick a method that's been used before (there are plenty of established processes in RIU).
Two things will happen:
1. It will probably work.
2. If it doesn't, and you post in here, people wont have to guess the answer, and you are likely to get a consensus, which will be meaningful.
Guessing often creates one of the famous "RIU squabbles", about whose guess was the best one.