To me it sounds like the nutrients are locked up or the roots are being attacked by fungus knats. See a bunch of knats? No, than the pH is off. Yes, you have to lime or you'll end up adjusting the pH, constantly. It is a lot easier to mix lime into the soil before you put your plant into it. Maybe someone will have good advise for adjusting your pH. I do not have that problem. I lime my soil and the pH stays there, for me. If the pH is off, the plants can't absorb the nutrients. Adding more nutrients will make things worse. They may need a good flush, have the pH adjusted and fertilizer.