You should have different nutes for both. Veg is like 15-10-10 and flowering you should use 10-15-10. Higher N for veg and higher P for flowering. As for ppm I have no educational value. Hope that helps a little bit.
Well I guess that would depend on your grow really. I mean if you let it veg forever you'll use more of those nutes, if you cut it short and flower early you may use more of those nutes. Mine is growing outdoors haven't done anything at all to it and it's coming along nicely. Happy gardening.
i just started flowering stage. veg lasted 4 weeks with no nutes at all. i figured that for that time all they needed was in the soil(plus water and lights of course). its weed after all! but if you veg longer than i would give em some ferts. im gonna start fertilizing during bloom though.
Plants early on in flowering will grow fast. You hear that they double or triple in size in flowering. Most of that happens early in flowering. So maybe more nutes during that growth spurt.
If in hydro, its kinda easy to tell (from what I've read, if ppm stays steady then its in harmony. IF the ppm rises, then the plants are using more water then nutes. If the ppm drops then the nutes are used more the water consumption. Correct me if I'm wrong or even friggin nuts)
If in soil, I'm at a loss (and I'm a dirt farmer) Maybe a 10% increase in nutes during spurts? Watch them leaf tips!