Would using unfiltered tap/well water be a possible cause for bottom leaves turning brown? I don't have much more information about the situation than this, as I'm asking for a friend and dont have all the details about their grow. I know that its a stealth cabinet grow using about 300W HPS. the inside is coated in plenty of reflecting white surfaces, so i dont think its a lighting issue. when I looked at it, they called it a hempy bucket technique, but it looked more like soil to me (instead of the more typical perm/verm hempy methods). Plants placed in 20oz bottles w/ the top cut off and a drain hole placed about 1/3 of the way up. i believe they are watering it everyday using tap water straight out the faucet.... Its in the country too, so the water might come from a well for all i know. The top leaves are green and happy. the bottom ones are starting to brown and feel very, very dry. The grower said there used to be more leaves like that, but they eventually had to cut them since they were pretty much dead Thanks in advance.
sounds like overwatering. Use 1/3 to 1/2 mix of perlite and overwatering is less of an issue, or let the pots dry out before watering.