I ran out of pH down buffer last week, so I haven't been lowering my pH in the last few weeks. The water I'm working with has a 7 pH level. Would this be ok until harvest or should I get more buffer solution?
It's cheap and you have at least 5 weeks left, likely 6 or 7. Get some more. A pH of 7 will severely affect what nutrients she can use. If you can't get buffer, you're better off catching rainwater and using that (it's usually more acidic).
it should be, but you can always use lemon juice to lower ph in a pinch, i would suggest keeping your ph where it should be, also if you dont you should be ok until harvest but you do have a little bit to go for that