How do I tell if I'm giving right amount of nutes


A question from a fellow grower:

I do have a couple of questions, first I use a PH meter, and a TDS meter to regulate my water and fert, I keep the TDS under 1200 and my PH 6.4-6.8, my question is how do I tell if my plants are receiving the proper amounts of water/fert. I check the leaves for burn but unsure what to look for, is there a schedule that can be followed to ensure proper watering . The second question is, I have done plant re-grows after the plant has been harvested, the plant usually grows very well and becomes very bushy with many grow points, what is your opinion of doing this?