nitrogen lockout????

first plant and by looking at previous posts it appears to be a nitrogen lockout?? my ph is about 7.5 and im working on that right now but i was just wondering whatcha thought.
im not using much nutrients because the soil came with it and everything else is alright.
is 7.5 high enough to cause that????
o ya and yes thats garlic......i had small gnats and that acually worked.....hmmm.
im not looking to invest alot im just doing this more or less as a learning experience....
thanx

[FONT=Times New Roman, Times, serif]pH problems can lockout nutrients. The wrong soil type can also cause nutrient lockout. Under the right conditions, even water can lockout nutrients. But these lockout causes occur rarely, and more than likely something other than what the cannabis plant needs has been added to the solution to cause this reaction.
When in doubt, transplant into fresh soil or a fresh hydroponic solution.[/FONT]

i havent added anything that it dosent need unless its not listed on the ingredients. i dont get it..... i havent checked it yet today but i started using alot better water since i found out that my city water sucks. hopefully that will help.... thank you for the advice and ill keep trying diff things.....