pH for solution used in soil is 6.0-7.0 personally I would aim for 6.5-7.0. pH for hydro solutions and coco is lower, more like 5.5-6.5 again preferably near the middle than the extremes. ppm in flowering is going to vary based on your plants, some are sensitive and will burn over 800, others are greedy and will tolerate 1200+. In hydro there are ways of testing the res and monitoring how the ppm changes to figure out whether you're too high or low. Veg ppm is lower, partly because the plant is a lot smaller for a while so it needs less food. Starting off around 250, rising to 600+ as the plant grows.