RDWC on a budget, never heard of such a thing. Dude dont panic. Someone will know what to do but it aint me.
PH looks good. Dont know what to tell yeah other than what i have already.
DWC is tenous if you monitor it daily. And when i say monitor it i mean Rez temp, PH, E.C and until you know what EC=What PPM, both. A sniff of the rez daily can even be a great clue as to whats going on.
If you want to make big girls an EC meter just makes it possible when 4 gallon of roots fill your 5 gallon rez and your working with a half a gallon of solution every 12 hours just to keep them wet, you need to know whats going in.
Without a meter chit i don't know what i would do.