Not sure if its Iron or -N?

[WizHigh]

Getting straight to the point with pics. I figure if its a nitrogen def then I have to up the dosage on N and turn on the heat at night because it gets a little cold in the room. The growth rate has slowed so im thinking its nitrogen def. I started to think well maybe its feeding on its self? Iron im not sure. Whats you guys take on this? Thanks for the help.

 

[Jimmycricket]

A few of the leaves look a tad on the pale side.

A little more nutes sounds good to me. Give them a small amount of P and K too.

 

[WizHigh]

Im giving them 4ml per gallon now. So whats the next dosage? and I guess ill add some bloom in there too. 2.5ml sound good.