im pretty sure SeeMoreBuds only vegged for about a month so the veg nutrients in his medium have been pumped into the plant and its basically flushed out the high nitrogen, and then he probably transplants to a bigger pot for flower with a lot of phosphorus and potassium in his new medium.
nutrients are pretty simple if you want to do it the natural and cheaper way. go to any nursery, hydro store, or plant store and youll see nutrients with 3 numbers(looks like #-#-#), this is known as NPK or nitrogen, phosphorus and potassium.
for veg, get some good guano/droppings/manure that has a good concentration of nitrogen over phosphorus, maybe a ratio like 3-1-1 or something along those lines. these will be sucked up by roots in up to 2 months, but i like to put more nutrients on the top soil before every water so theres plenty for the whole plant.
theres also another method of making something called organic tea, i think it helps nutrients get to the roots faster, but it might be a little more complex for beginners. take a hand full of soil and drop it in a bucket with a table spoon of blackstrap molasses (or i use organic honey when im low on molasses) and an airstone. this will make the water really aerated and the microbes will reproduce over 2 days. try to keep it in a warm place so the microbes can thrive.
for flower, get some nutrients with a ration of 0-3-3, since nitrogen isn't really needed too much in flower. but some people think they do but theres just enough in their medium as is. and add as much nutrients as you can as flower moves on, get a ppm meter for you water if you using chemical nutrients so you cant get any burns. organic flowering nutes are usually guano and blood meal/bone meal.
id recommend organics, no nute lock, no burns, and they usually lower your pH to around the comfort level(6.2-6.6 imo) when added to your water but some blood meals can raise it. just always check it pH attentively and make it a habit before you go watering your plants.
