I truly hope this doesn't come off as harsh or sharp in any way but your knowledge regarding practically every aspect of what you want to do seems to be completely unknown to you. If you're serious, sit down assess the market and current economic state, learn everything you can about starting a business since you seemed unaware how taxes came into play, and make a well though out plan as to how to accomplish this endeavor. You've asked very basic questions in your previous thread as well as this one. Why haven't you already researched most of this? You're depending instead on strangers online who all gave different opinions on what you should be growing and the difficulty. I think you really need to study up on marketing, business in general, economics, the way this particular industry operates, projected ROI and other returns/debts, and the associated legalities.
I think you should tediously study those topics if you actually want to do this. Later after having gained much more knowledge, you can as others who have done similar things specific questions unlike "what are the best corals for me to grow".