Do I need Nutes?

im about 1 month in and have not added any nutrients. I am using a local soil from a hydro shop. I am watering from the faucet and do not know my ph. one plant has all of its lower leaves turning yellow (the first 2 pics) while the other is just showing yellow on the tips of a few leaves. All other plants are fine. Is it more likely im causing a lockout with bad water or its just time for some nutrients? Im 4 days into flower and plan on adding nutes very soon. Any help would be great!

You really need either a PH test kit or meter. (You prolly already know) I'd be giving them some watered down nute solution after you establish your PH.