Hi lazy smoker 7 Im not as clued up a stinky but i have grown big bud a few times.big bud is around 8% thc but dont let that fool you she has one kick ass knock out stone.she is a very easy plant to grow and is very forgivable when problems arise.I vegged a big bud for 7 weeks and got 8 oz from her under 1600 watss hps.nothernlights and aurora indica are easy strains and good frist time strains very high yeilders and kick ass stones.Rain water is ok if the ph is ok our rain water has a pH of 5.5 a bit to low for soil but perfect for hydro though ive never used it hydro.Just check the ph and get it right for what ever medium u are using.Though some have reported having probs with rain water i have had none myself while using it .If using tap water let it sit at least 24 hours to remove the fluoride form it cause this causes lock out in Mg,Mn and zinc. hope this is helpfull as i said im no stinky lol.be safe the postman.