Look, whole thing its just simple. You have nutes which tell you they have all you need and ratio (formula) you must follow. You can lower the dosage but not change the ratios its about balance. You can go half dose but all three parts not only one or two. Always start half reccomended, you can always add more but not opposite. You plant your seed and just water, no pHing, be careful of overwatering as well as underwatering and when your lower leaves start to look like this one on the last pic it is time to feed, forget about the time weeks and schedules, just follow your plant. Keep it simple is the way...