On December 1, 1936, U.S. Patent 2,062,755 issued to Frank F. Lyons and Ernest Brundin on a System of Water Culture:

Water culture, or hydroponics, involves growing plants without soil by using water-based mineral nutrient solutions in an artificial environment. The earliest published work on growing plants without soil was Sylva Sylvarum (A Natural History) by Francis Bacon, published in 1627 a year after the author’s death. Hydroponics remained a popular topic of research ever since.

In 1929, William Frederick Gericke of the University of California at Berkeley began promoting that the principles of hydroponics crop production. Dr. Gericke had warmed the nutrient solution of his tanks with soil-heating cables, believing that warming the nutrient temperature would increase growth. This was impractically expensive, but Brundin co-inventor of the ‘755 patent, proposed heating the solution with a steam boiler, and mechanically pumping the warmed solution to the growing beds, as disclosed in the ‘755 patent.

Brundin continued to make improvements to hydroponics, and obtained at least one more patent U.S. Patent No. 2,249,197: