Underwhelming Harvest from 1st Grow

My first grow was Northern Lights & Dieselicious.

I knew the plants were smaller then I would have liked them to be but I didn’t foresee the yield being what it was.

Yield:

Northern – 50g

Dieselicious - 35g

Northern

Dieselicious

Here are my questions & concerns. Some of the nugs are beautiful but it’s entirely too fluffy. Northern was a little fluffier than Dieselicious. I don’t know if they are just those kind of strains or what. What factors go into having denser buds? What do I need to do to get my plant & bugs bigger so that my yield is higher?

I’m using general hydroponics & have a 600w LED light in my flowering tent.

Let me know what other information you need to help you help me.

Thank you