If theres any medical cannabis growers out there, i need help saving my plant!?

IMPORTANT: if you dont intind to answer the question with respect dont answer at all. anyways i have a little over 2 month old indoor medical cannabis plant. although i dont have a pic il try to explain it... its about over a foot tall, it looks like a thick bush, the cannopy is really full and theres a ton of leaves comming in everywere, not including the huge fan leaves all over and the ones comming out the top, theres alot of thick stems and little full pot leaves shouting out from every node, to were you can barely even see the stem which is about almost an inch thick, but recently ive noticed that every leaf is starting to brown at the edges, its even starting on the tips of the new ones coming in. we have compleatly inspected it for any bugs. we dont use any exta nutrients. we have it in a large 5 or more gallon bucket, with miracle grow potting soil, and we water it every other day to every three days depending on how wet the soil is. the lights are about two feet above it, and when i put my hand under its barely warm, and the temp in the growroom, stays around 75 degrees f. so i dont understand whats going on. can any one help me? also we have clipped about 6 of the bottom leaves, 4 fan leaves, and 2 that were from the stems comming from the node like two weeks ago. for humitity we keep a bowl of water in the room and mist the plant every now and then. please help me figure out why the leaves are doing this! i greatly appreciate every bit of help i can get!