well, to give my humble opinion on ferts. this is how I see it. (this way you'll choose ferts in the future that fit the cycle its in):
three major nutrients needed by plants: Nitrogen (N), Phosphorus (P), and Potassium (K)
(N) the first number (P) the second and (K) the third.
for veg. a fertilizer should have roughly twice as much N as it does P and K.
for the flowering cycle your plants need a high Phosphorous (P) food. It does not need much (N) in this cycle. So you want to keep this down to a minimum.
So in a nut shell use the 24-8-16 for veg. I would look into ferts such as fox farms as they have a complete set that will see you through a full grow. When the plant is in flower it will not use up the (N) using 20-20-20 or the other nUt 24-8-16 which will cause a build-up and cause a nutrient overdose unless flushed. IMHO.
