I am having problems with my plants. I have a 400 watt light in a 5x9 room, the room temp is 75-78 degrees with good air ventilation. I am using an hydro system that feeds my plants 4 times a day for 10 mins. I maintain the ph between 6.6 and 7.0 The leaves on my plant are shriviling up and they have yellow spots. I was told it might be a nutrient problem so I flushed the plant with water and cut down on the nutrients. I have a 15 gallon resivior and add nutrients for a 13 gallons. How can I tell if they are getting better? Will the leaves turn green again? Do I go based on the new leaves growing?
New growth should be OK. Older leaves should stay the same.(dead spots won't regain colour) Check its not spreading to other older growth.