New fish farm setup

[Macaireb]

Hey all,

My father owns several acres of land with a stream running through it. I've spent hours and hours thinking of a way to set of farming. The land is here and my rough plan is as follows. Using a shovel, bucket, climbing rope and a combination of simple machines set up a 8 foot underground cube next to the stream.

I plan to place a concrete dam at the entry point, and I'm still working out the logistics and shall do so for at-least the next month. I need insight on the setup and also how to feed the fish, keep the enviroment safe, and get a vendor's license to sell them.

Thanks for reading this over