Hey guys ,

Hey guys ,
I am at 5 to 6 week of flowering now , i have one of my plant that starting to show yellow leaves and a lot of tiny brown spots on them , and the worst , they start to fall one by one especially the lower ones, and the disease seems to spread on the newer leaves , i need help , this has caused a massive defoliation of the plant :

Here is what the leaves look like :

IMG_20180514_132233.jpg IMG_20180514_132350.jpg IMG_20180514_132404.jpg IMG_20180514_132122_BURST003.jpg

They become crispy with random brown spots, the disease is progressing from the bottom to top , that thing is unstoppable , every day leaves are falling .

The strain is critical chesse from dina , the medium is a classic bio soil / terraneous ( mix of Sphagnum, green compost , vegetable matters) that contain nitrogen 280g/m3 ; and phosphorus pentoxide (P2O5) 180g/m3 with a PH of 6.4, conductivity of 45 mS/m , i use HPS green power 400w , light schedule is 12/12 since four weeks now ,
temps are 86F during light and 64F during night , RH is low somewhere in the 40 to 50 % range , i give them bottled water with a basic PH of 7 , but i use PH down from general hydro to lower the PH at 6.5 and then add some nutes and feed them directly.

For the feeding schedule i use bio bloom(2.5mL/L) and a litte of bio grow ( 1mL/L ) every 4 days since the beginning of the flowering period, and between just bottled water with PH down .So basically i feed them every 4 days and watering them every 2 days.

Thanks .