Aquaponics is a method of organic farming that can be used indoors as well as outdoors, in areas of any size. This allows people to grow their own organic crops that does not use any external chemical fertilizers.
Chemical fertilizers are known to cause adverse effects on human body.
Here's how the system looks like:
Aquaponics System Overview
The system consists of two tubs. The tub in the bottom would have water and fishes in it. The tub at the top would have plants in it. Plants can either planted into pots or planted directly into the tub at the top. Care should be taken that there's gravel placed below the sand so that the sand does not seep in through the holes in the pot or the tub, with the excess water flowing out of the tub or the pots and enter the fish tank.
The water in the tub bellow will be mixed with the waste produced by the fish in the water. This water will be pumped up to the upper tub with plants, using a submersible pump. Holes will be made in the pipe through which the water is pumped from the lower tub enters the upper tub and sprinkles over the plants. As the water enters the soil, the fish waste will nitrify the soil. So, fish waste will act as natural manure for the soil. Then, the excess water will seep down the soil, enter the layer of gravel, where the excess soil particles get filtered out, and the fresh-water that comes out of the hole in the pot/tub will fall back into the tub that has the fishes. This water will be oxygen-rich, so there would be no need for an external aerator for the fish tank. This system also cleans the water in the fish tank automatically as the system runs, so the users don't have to clean the water in the fish tank regularly.
Here's a video demonstrating the process as well as the use of various sensors and actuators:
And here is another video of me walking through the working of the IoT dashboard.