Shagrathanswered grow question 4 years ago Hi there!
For THE BEST control of your growth and THE cheapest I suggest you learn to use salts. I donät know where you are based at but for example Jacks hydro has the good stuff. Basically you need only these two: https://www.jacksnutrients.com/online-store/Cal-Nit-Part-B-p101272606 https://www.jacksnutrients.com/online-store/5-12-26-Part-A-p101272607 and maybe some MgSO4 (Magnesium Sulfate, Epsom salt)
From my experince from two grows and watchin others I think that additives palys more important role on keepint it constant and you only need to provide balanced amount of basic nutes.
For example I calculate my nutes in PPM's and when REALLY simplified in full veg I use something like 250:60:250 NPK as PPM and in flowering 80-120:60:250
I also use lots of additives and beneficial bacteria so these numbers might not work for you but just and example