Fungus or Nutrient burn or Deficiency? Help!

I have 5 total plants, and 2 of them (Bullrider strain) have started to develop brown spots along the veins. Some of the leaves are taken over by the brown spots at the tip of the leaf and curling at the ends. The leaves are also really crispy. Its affecting mostly the middle topish growth. I am using 400 watt HPS, 4th week of flowering, using floraNova every 3rd watering, watering everyday to every other day with reverse osmosis water. The lights are about 10-12 inches away from plants. Im not sure what it is and could really use some insight. Thanks a lot!

I forgot to ad that humidity is 45%, and temp averages at about 76. Sometimes a little higher.

This is one of the problems with most ferts - they don't really tell you how often to use the product. I think you've given too much fert. You don't say exactly how much you're giving and how much soil there in, etc., but I'm guessing that from the appearance and what you write, that you've given too much fert. Watering alot to the point where the soil is always wet tends to be frowned on, because you want the soil to dry out some. This allows air to get in the soil, which is good for roots. I guess people think they can follow a "feeding schedule" with success but I really don't think it works that way. Seems like most schedules will screw things up. Just rinse the soil pretty good with water and let it dry out some. I'm not sure what else to tell you as you didn't give alot of details, but I suspect step one is to cut back on the food.

are you using a calmag supplement (or molasses) with your RO water? looks (and sounds) like a magnesium deficiency to me.

usually it's better to fill out the troubleshooting form (link in my sig) to get better, more accurate advice. think this one is solved though.


-shake