Lucas Formula should be used in the same ratio throughout the grow. There is a misconception that one should use 5ml of Micro and 10ml of Bloom, when in veg, and switch to 8ml of Micro, and 16ml of Bloom, when flowering.I am by no means of an authority but when I was just switching to hydro the Lucas formula and general hydroponics micro and bloom were great. I had so many other factors to dial in the simplicity of the nute program was beneficial to me. It's just 0/5/10 for veg and 0/8/16 for flower. That's 0 ml per gal of grow (don't need it the micro and bloom in the higher doses provide everything) 5ml micro and 10ml bloom. Cheap and effective. But that's just one route to go.