This book begins by describing the irrigation management techniques that are currently used for scheduling irrigation in a hydroponic culture, presented in Chapter One. Chapter Two covers research information about the nitrogen forms used in hydroponics, their relationships and peculiarities, as well as information on the use of silicon, its available sources and role in mitigating the toxic effects of ammonium. In Chapter Three, Centella asiatica was tested for the effects of Pb exposure on Cu accumulation and antioxidant activities which includes the activities of ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and guaiacol peroxidase (GPX). Chapter Four discusses the phytoextraction potential of the free floating aquatic plant for heavy metals from aqueous solution. Chapter Five analyses the use of wastewaters to formulate nutritive solutions represents a rational alternative to wastewaters disposal and adds value to what is currently considered a waste product. Chapter Six provides a brief review of hydroponics used in fishery waste reuse. Chapter Seven discusses the results of physicochemical characterisation of Human urine, Cassava Wastewater and alternative nutrient solution prepared through these effluents as an alternative for its use in agroecological systems of agricultural cultivation. Chapter Eight describes recent progress and findings on the hydroponic culture of edible Opuntia. Finally, the book concludes with an expert commentary that argues that plant factories are powerful tools to cultivate and improve the quality of edible cacti.