between the 3 and 4th week of flowering, small spots start to form on the larger fan leaves. this very quickly spreads to the rest of the crowd within 1 week. The small spots are visible on both sides of the leaf, and tend to be in between the viens, atfer 3-4 days as it is spreading, the leaf starts to curl upward starting from the tip to the center of the leaf. the leaf is brown and with black spots and supplies no nutrients to the plant. this problem eventually takes over the whole plant leaving no fan leaves. The room is perfect... it is sanitized between crops; temp 78F, 50%RH, 6.3ph, 1800ppm balanced food, 1800ppm co2 and are acuate and constant. soil is not reused, everything is done to keep the place spotless. plants show vigorus healthy growth. i feel that this disease/virus is airborn. please help as i have no other solutions no it is not pythium, rot, mildue, nutrient lockout or any other common problem. this is something that is very complex and is not to be answered without thought. pictures will follow for anyone that is willing to help me battle this unknown cure. thanks...
trust me, overfeeding is not the problem, and venting is neither the problem. like i said, this is a complex disease, not your common daily easy solvable one!
this looks like the same thing that happened to my melon crop this year, powdery mildew. Its a guess, but this is what i get from the pics. take care.
I have the same problem, I have juststarted flowering 2 days ago. This problem only happens to my lower fans. I use a hydro system, you? I also have a specifically designed grow room just for the plants, not animals allowed, all fresh air is hepa filtered . But I am starting to get the same prob, I think my spots on the lower fans came from when I used co2. I have quit useing it so the spots are only on the lower fans. I suggest that you lower the usage of co2 to maybe once or twice a week at 1800 or what ever you were using. Either that or lower the amount of co2 used
ok, enough, i change my avatar now. I just thought the woman was hot, not to portray my gender... lol Take care, and when you figure it out let us know. it would be interesting to know what kind of unbasic non common problem it really was, lol. i am a sarcastic dick, i apologize, really.
pushing the plant to the limit is what you want... once the leave tips start to burn, then you know that you have given them too much fertz. As for spider mites... that is not the problem! As for the CO2 PPM's being to high... they should be equal to the PPM's of the food that you are feeding them. i have given up on finding the problem, changed to a new strain. thanks for the input of everyone!
What kind of water do u use? I bet ur using tap water! Get distilled. If that ain't it tell me then we will both know wtf it is.