1. Research the local market. This will dictate what vegetables and fish to grow. You want to choose the ones with a high demand, high price, and possibly low competition. Of course, do not choose a fish/vegetable species that requires climatic conditions that are very different from what you have in the area. For example, tilapia require warm temperatures, and if you live in cold areas you'll have to spend significantly on heating to grow these; a better option would be trout. In addition, you may consider growing fish to sell them as pets instead of food: in many areas there is a considerable demand for goldfish, for example. Same when it comes to plants: in some areas, you'll find that it is more profitable to grow herbs instead of vegetables. In addition, it is usually profitable to grow off season produce, but this will require heating (and hence heating costs). It's all about finding the optimal balance to maximize profits. Do your research properly.

2. Find your customers. If you sell directly to the consumers, you'll get to keep all your profits, but it can be a hassle. Instead, you can get a deal from a local grocery/fish monger and you can sell all you produce to them. However, you'll have to give them a lower price than what you'll give to direct clients. If you are selling fish as pets, consider placing an advertisement in your local newspaper.

3. Start small, think big. No matter how thorough your research, only when you'll actually start your venture you'll get to know all the things involved and the profit margin. Therefore, you should start small, as this will give you the flexibility to adapt. It's also easier to run a smaller system, and if you are new to Aquaponics you'll have some learning to do to run it efficiently. In addition, when you're just starting out, things will go wrong and it is easier to fix them on a small scale than if you are running a massive Aquaponics farm.