It is not true.
If you want to survive, you have to know what will grow successfully when. If you are in Montana and there is three feet of snow on the ground, you cant grow a tomato with aquaponics unless you control the environment. The self sustaining nature of aquaponics will not allow that tomato to survive the cold unless you do something to control the temperature. You need to know the agricultural zone in which you live. To find your zone number, go to USDA Plant Hardiness Map and enter your ZIP code. Memorize this number. When you are researching plants and seeds, the provider will always tell you in what zones the plants will grow. Staying within your zone will contribute to your success. Staying within your season is also important. Just like the guys in Montana cant grow tomatoes in winter because of the cold, I cant grow cucurbits (like cucumbers, melons, squash) in summer because the air temperature is just too hot.
That means you need to learn about both growing the fish and growing the plants. For example, we recently had heavy rains (quite normal for our south Florida summer) and as a result some of my plants (both soil and aquaponic) were infested with powdery mildew. Just because the plants were in aquaponic systems did not make them immune from the mildew. In this case, all I did was remove the infected parts (they did NOT go in the compost) and the plants recovered quickly because I acted quickly. If necessary, I could have sprayed with a solution of baking soda and water (keeping an eye on the pH fo my water). The point is no matter if the plant is in soil or not, you need to know how to take care of the plants, because if you have a garden you will have pests and diseases. Your goal is to minimize these while maximizing yield. That is where aquaponics comes into play. You are going for high yield because you are using your animal protein growing system to provide the food for the plants, thus providing constant nutrition to the plants.
Another question I read was from someone who wanted to know why the seeds his neighbor have him werent performing like the neighbors plants. Well, if your friends give you the seeds of their hybrid plants, you cant expect them to perform the same. No matter if the plant is growing in aquaponics or soil, you cant save the seeds of hybrids and expect them to reproduce true. Always use heirloom or non-hybrid seeds. Learn to dry and save your own seeds. When someone offers you seed, ask them about their source.
