It seemed my plant suffered nitrogen toxicity. I shouldn't have added organic nutrition pellet to the soil. I used very little "easy grow tab" just one time before I noticed nitrogen toxicity. I think it is better not use any kind of fertilizer when growing autos.
I DO NOT RECCOMEND THIS LIGHT. This is absolutely crap. It get too hot, you can't even touch it with your hand. The temperature inside my little tent reached 34°c and the plant suffered a lot from heat stress. Wasted money.