I have been growing for ca. 20 years. The last 5 years i have been growing hydroponically. I have 2 plants growing in a 70 liter reservoir, with 2 airpumps. I am using Canna Aqua nutrients that has self-stabilizing ph. Light is 2 quantum-boards 480 watts. The 2 plants are in the same nutrient solution and have the same airstone and air-pressure, but one of the plants have brown spots on lower and middle leaf and the other plant has no deficiencies. This is usually ph-fluctuations, but it is only on one of the plants. I have checked the ph - and it is within range. The plants are 3 weeks into veg. Does anyone have this issue ? Or can someone tell me whats going on.
Looks like that plant is overly sensitive to something, food, light or pH. Checking all of those might shed light on the issue. Too much fertilizer is the most likely problem. My usual strategy is to back off of everything to fix problems. I've never had a deficiency in hydro.
I agree, it looks like phosphorus deficiency. But i have ruled out this : Ph is correct, nutrient levels are good, water temp and air temp is good. But since i just got a new more powerful light, I think i am gonna try to increase the nutrient levels a bit. adding a picture of both plants (Ghost train haze) The white papers is there to keep the water temp below 21 degrees c.