Hydroponics came into public view way back in 1929 when a University of Berkley professor Dr. William F Gericke was photographed on a ladder picking tomatoes from a 25-foot plant growing out of a washtub. 

It was Dr. Gericke who coined the term “hydroponics” which translated from two Greek words means “water working”. Gericke's “Complete Guide to Soilless Gardening”, published in 1941, showed Dr. Gericke standing in front of a hydroponic system that produced 1224 lbs. of tomatoes in 130 square feet.

Since the 1940's there has been tremendous advances and developments in hydroponic plant culture. In the decades that have followed with the development of new materials and new technology geared toward the advancement of hydroponic plant culture. There are literally hundreds of different systems to grow plants and deliver nutrients to the plants roots.

Hydroponics can be defined as the science of growing plants without soil, although inert medias are often used in the hydro...

THE LAW OF LIMITING FACTORS

There are five factors that promote a plant’s growth.  If we want a plant to respond well, we need to provide the optimum characteristics of ALL of these factors.  You could be doing well on four of the five factors, but if that fifth factor isn’t optimized, it will limit that plant’s growth.

The good news is, if there’s a problem and the plant isn’t responding well, we can begin to isolate each factor, and figure out which one is causing the problem and how to solve it.

THE FIVE LIMITING FACTORS:

• Air quality
• Water quality
• Nutrients/feed
• Light
• Growing media

1. AIR QUALITY

On a basic level, air quality involves O2 and CO2 content, but there are other aspects, as well.

For example, if someone had their growing operation next to a bus depot and all the fumes were getting into the plants’ air, it would create serious problems.

I’ll talk about CO2 and carbon in the next post, and how some growers are adding CO2 to their air systems and seeing i...