I disagree with telling someone not to worry about TDS or EC. It is a very good idea to keep up with the strength of your run off in soil type grows. Not to mention that if you mix nutes you need to know how strong they are.

Also. Once in flower, never mix nutes 1/2 strength. If it were meant to be applied that way, the instructions would read that way. When I grow a soil type grow using a mix like foxfarm; I do not add nutrients in veg at all generally. I start to add nutrients when I change photperiod.