Hi. The plants in question are Sensi Skunk auto and Auto tutankhamon. They are in bloom already under hps 250 watts. Watering is done with dehumidifier water, PH Grated, plus fertilizers (which I do not run with a program.)
Temperatures with lights ON (26-29 celcius)
Temperatures with lights OFF (19-20 celcius)
The fertilizers I use are not some well-known company but the following
(almost added with every watering)
(for flowering stage)
And some photos:
Sensi skunk auto: (light distance from plant 38 cm/15 inches)
The actual problem is the yellowing of the top leaves and a small twist on leaves tips.
Auto tutankhamon: (light distance from plant 45 cm/18 inches)
Same problem here with the top leaves being lighter green/yellow.