I'm using tap water with a beginning of 120 PPM. My roots are fine. Nice and white. The plant seems to be growing fast it's just ugly as hell with the browning. I added a little Epsom salt 2 days ago. The only other thing I can come up with is not enough fresh air. I'm growing in a steel locking garage style cabinet. The inside dimensions are 6 foot tall, 3 foot wide, and 18 inches deep. I installed 2 80 mm computer style fans as the exhaust near the top of the cabinet. Towards the bottom I installed 1 80 mm intake computer style fan. I usually leave the doors open while I'm home but closed and locked while at work and shit. Stealth is kind of an issue but aybe I need to cut some kind of passive intake and install an additional exhaust. I'm really scratching my head here because I've tried everything else. I'm stumped because both my first and second grow have the exact same problem even though they're different strains.