I started out with commercial fertilizers, but I also started out on hydroponics several months ago. I would like to suggest a couple of areas to investigate. One of them would be composted chicken manure, the other being seaweed.
In the short time I have been doing this, I have been working with tomatoes, cucumbers, green beans and lettuce. I have had a bit of a problem with the amount of concentration of these two natural fertilizers, but I am committed to learning how to do so. The one thing I learned, after a few off balances that damaged my plants, was that I got a much larger rate of growth and a much healthier plant after I switched. I am not an advocate of "total organic" but it seemed to me that I could get better results, because I had to learn what the plants need, and tailored the nutrients accordingly. The commercial fertilizers seemed to be too standardized.
When I embarked upon this journey (grew up on a farm, and have grown vegetable gardens ever since), I did so as a challenge. I did so with the full understanding that I did not know what I was doing, and that I was committed to learn (question at the top of this forum). I intend to get into commercial growing so efficiency has to be my goal, no matter how much I need to learn.
I know, what I don't know. If I believe it to be truth, I have proved it with scientific examination, which is available 100% of the time.