This number is variable, so I will go off of the history of my business, Aquatic Designs, Inc.
Once established, one can easily earn from $50 – $75 per hour or more. They could eventually break six figures in sales as a sole employee and even higher with employees. The business can be profitable well within a year with just a few accounts (5 or less depending on expenses such as licenses, accounting, insurance or the size of aquariums).
Currently, I earn an average of $85 per hour and gross over $70,000 per year with a 75% profit margin. I average around 16 hours per week doing aquarium maintenance. This is in addition to some other side hustles.
You can find more information about this in the free workshop here.