Soil grow: mid 6's
Hydro growz: well yer in trouble if you dont have a ph and a ppm meter

You should be ok, maybe, probably have time. I actally have a little story, b/c im doing my first grow in my *new* house. I was running into all kinds of crap id never seen before, finally broke down and did some ph testing, my tap water runs at about 8.8! its crazy high. So I just recently went thru my first ph experience ever. However, I didnt notice any defs until about the 3rd week in veg and it was quickly cleared by some foliar spraying and yup, vinegar. So you should be ok.