First time ever growing - Dark Devil

So since this is my first time growing weed in any form or way I do not have a lot of knowledge. I have been growing this strain since the 4th of june and I think it is going very good, In my opinion at least. 😊 I do not use any nutritions but i do make sure my water is the right PH. What I am wondering about tho is the way it is growing. I feel like for the weeks they are in they should be bigger? Any suggestions on what I should do or change about my routine for growing larger and bigger yields? Much love, Nien 😘