Let's get "ponics" out of the way first. "Ponics" has a Greek root, ponein, "to labor or toil." So in our vocabulary, it means work.
Thus, a logical conclusion would be that they both are synonyms for "waterworks."
But when we adopt terms to describe things, we bend or adapt definitions to differentiate what we are doing. Hydroponics is universally used to describe the growing of plants in water without soil. A far cry from "waterworks," but it has become an accepted term for this type of agriculture. Hydroponics farms are popping up all over. Popular with pot growers, it is also a highly efficient method for producing tomatoes, cucumbers, lettuce, and other leafy greens.
In hydroponics, the roots of the plants are suspended in flowing water to which nutrients necessary for healthy plant growth have been added. Since there is no nutrient-rich soil, salts and essential chemical elements have to be added to fertilize the growth of the plants.
While enabling the growth of plants and crops with short growth cycles, hydroponics has a few shortcomings: (1) it is necessary to add chemical nutrients. These can be expensive and their production is not very sustainable. Many are mined and are in short supply. (2) The chemicals build up in the growth systems and have to be flushed out of the grow beds together with the water every now and again. Also not a very environmentally sound practice. And (3) plants grown this way, are not certifiably "organic." This presents a major problem in the market place for hydroponic farmers trying to compete with soil-based organic farmers.
In my next blog, I'll describe aquaponics and discuss what I believe to be its advantages over hydroponics.