Hi everyone, I'm a noob to the sight and growing in dirt. I have grown on rockwool for quit some time so I'm not a complete greenhorn and kept mothers in promix. I have started 4 plants about a couple months ago and three of them have been getting sick. I planted them in ffof. Out of four strains in the same room three of them have the same symptoms. It started with one strain and has slowly spread to the other ones except the last. Fourth strain is super healthy. Starts out on the older fan leaves as small rust spots. Then the leave starts to curl up and die with the growth slowing down In the plant. Then eventually spreading to all of the fan leaves. I have been keeping my ph fluctuating 6.2- 6.8, room temp is 77-73F with good air circulation, lights are about 2ft away. I have tried giving them cal/mag, flushing, feeding and even spraying for bugs/fungi even though no signs of bugs. I even bought a soil ph/ moister tester to make sure I'm not over watering. I water about every 2-3 days. Not sure what is going on. Hoping someone has seen/ had this problem and can help out with some advise.