why fertilize if medium has it all?

K, i'm learing from an old teacher, while trying to learn on RIU. We're using sunshine #4 mix. Have been since she was cloned. 6 weeks now. My teacher says she's growing slow. Anyway, i've been reading so much on fert. when/what/ how much. My teacher says with the right medium, no need for fert. Its in the medium. Why would anybody want to add more? Is my teacher old school? We started off bad. 1 out of twenty clippings survived. He was really good at it, in his time.

sounds like your teacher may be pointing you in the wrong direction, if you wanna know exactly what is going into your medium i would recommend a soil less mix like promix. But yes i have heard if you have the right mix you never have to add food, never tried it but have read about it

its all about nutrient uptake. Some mediums provide them in a little more abundance than others. Some provide them organically, some provide them chemically. Some not at all. Like in an instance for using hydro, and the nutrients must be supplied manually. But providing your plants with the maximum amount of nutrients without over-doing it would be the ideal situation. It all depends on your medium, growing practices, and personal taste. A little experience wouldn't hurt either...

yeppers......

older growers usually have experience, but the dynamics of the whole operation has changed so much in the last few years, let alone thirty years.
what he is telling you about soil is wrong. premixed soil always has nutrients in it, but the plant uses all those nutrients. then what? plus, the amount of nutrients in soil may be good to start plants, but will do nothing for flowering them.

They dont make a medium that you dont have to fertilize,I use oceans forest and worm castings and still have to feed weekly.In order to not fertilize you have to add castings, guano,kelp, blood and bone meal.I just buy the soil and castings and use PH balanced organic nutes

she looks real healthy. all new growing is the lime green and old is dark and healthy looking. no sign of sickness.