Related Experiment Video
Updated: Jan 30, 2026

Hydroponics: A Versatile System to Study Nutrient Allocation and Plant Responses to Nutrient Availability and Exposure to Toxic Elements
Published on: July 13, 2016
Construction of an Automatic Nutrient Solution Management System for Hydroponics-Adjustment of the K+-Concentration
Kebin Xu1, Yuki Kitazumi1, Kenji Kano1
1Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University.
Abstract:
An automatic management system for nutrient solutions was constructed using a programmable logic controller (PLC) and a K+-ion selective electrode (K+-ISE). The concentration of K+ was monitored by the K+-ISE. When the concentration of K+ fell to the threshold limit, an appropriate amount of a concentrated K+ solution was added to the hydroponic solution. The volume was also maintained at a constant level by addition of water. This system can be constructed simply and inexpensively without any computers and pumps.
Related Concept Videos
Solution Concentration and Dilution
Expressing Solution Concentration
Concentrations may be quantitatively assessed using a wide variety of measurement units, each convenient for particular applications. Molarity (M) is a useful concentration unit for many applications in chemistry.
Automatic Processing and Automatic Social Behavior
Concentration Cells
Consider the following voltaic cell:
Water and Mineral Acquisition
Weak Base Solutions

