Hello. First, I want to say both of the previous answers are correct. Deficiency can be caused by too much nutrients, and you do have signs of overwatering, however the most common mistake is incorrect ph. For soil, I agree with
@ValhallasGarden that 6.5-6.8 is the range you need to dial in. This is most important.
Second,
@Athos is right about letting the plants suck up existing nutrients from a nice, healthy potting soil. You should not need to add much nutrients in the first 4-5 weeks if you start with good soil. Then, you add small percentages of recommended nutrients and watch how the plants react. I have been guilty of going overboard with the nutes and using incorrect ph multiple times and it always turns out bad. Less is more with nutrients in soil. Good luck, and please pick one of the other guys as your grow answer, not mine. They provided the answer between both of them.