never heard of compost in three weeks thg. i make my own medium by composting. but on a larger scale so i can run thru a winter grow season. i finished my first all organic grow on xmas. i've been fooling with it a little at a time for a few years...
my mix is very very simple, with no expense but the fuel to run a mower. i add equal amounts of fresh cut green grass to brown mulched leaves(this is where a push mower with bagger is handy, because the smaller you can break it down, the faster it will compost). to this i add a heaping spade shovel full of ash from burnt wood per each wheelbarrel full of mulch. thats it. i feed the pile with proper scraps(mostly fruit rinds, juices) put that in the sun and let the pile or heap 'cook' for two weeks. when you add browns to greens , decomp takes place, and inside the heap will get very warm as it kills of seeds from seed plants.i believe it reaches temps around 160 degrees...
while it cooks dont disturb it for two weeks, then mix with pitchfork however often you like. at least twice per month. (i'll mix weekly if i have lots of scraps to add). in place of brown mulched leaves, you can also used plain newspaper with black and white print shredded, (no glossy), brown cardboard(again no glossy), or a mix of different browns to greens...
as long as theres a food source in the heap nature will take its coursein breaking it down into black gold...
i never add anything else to the heap until it is fully broken down. your blend should be free of any sticks. some people shake this through screens, i cook all summer, so i have several heaps in different stages always set up and running.
after it is broken down you can add the 'spices' to it and begin to cook that if you choose. i think that is the three week cook you speak of hearing about thg?
i run mine with no further additives until the plants are ready to feed...just grass, brown mulch leaves, pot ash...thats it!
i run a blend for veg, and a different blend for flower...i transplant from one to the other as plants go into flower room.
depending on how many plants you grow indoors, and pot size, you can save some serious cash by making your own blend thru composting. i saved $660 last year, and about same this year already.
also, its easier to hand mix right on the ground if possible i think...for smaller batches a 55gal. barrel is perfect...
there are alot of vids on the tube for composting...
heres a pic of a girl run in this blend and harvested on xmas...>>>
hope this helped you out if nothing else just another view...peace...