Whats wrong with my plants? Help

[bazookajoe1]

ive been growing some AK48 strain i got from amsterdam. there feminized seeds and im in week 3 plants are about 10 inches tall. so far everything is okay but now my leaves are changing colors and spots on them yellow spots almost look like there getting burned. plant is 5inch away from lights and barley heat coming off them. yellowish bloches on only few leaves. please help me

week 3 AK48
75-80 degrees 2 fans inside a grow box


24/7 lights flourecent bulbs and LED purple and blue
water every 3 days every third watering i use nutrients. 420 Magazine

 

[Jimmycricket]

not enough Potash

Molasses would work just fine. or sul po mag or anything with high P content.