yea,these coco disks seem very dirty,when i got the system,i had to clean a bunch of loose stuff out of the pcv tubes. i was just debating because for me to fill all my pots,its gonna take 40 of the big cubes of rockwool,i'm figuring at least $150-$200.I think my hydroponic shop wants $7 or $8 for each cube of rockwool.so which leads me to my question,does anybody know of a website online that has good rockwool prices? thanks for the help and i hope to have this under way within the next month or so.i'll start a journal when the time arrives.i see alot of people in here doin 3-10 plants but i have yet to see someone attempting 40. (WILL PROBABLY END UP BEING AROUND 20 ONCE I KILL THE MALES BUT... WHO KNOWS) anyways,thanks for the advise-G_48911