Abstract
Water is ubiquitous in nature and it may be from this property that it is frequently taken for granted. For the last few decades, researchers have been differentiating "bulk water" from other forms of water and there is now a name for this other water presently referred to as Exclusive Zone or EZ water. It is also called structured water, energy water, reactivated water, activated water, etc. The studies on some physico – chemical parameters and bacterial growth in the gut of Catfish (Clarias gariepinus) Fingerlings reared in structured and unstructured water was carried out in the Zoology Laboratory of Nasarawa State University Keffi. Water temperature was analyzed using a dry mercury thermometer. Dissolved Oxygen and Biological Oxygen Demand (BOD) were determined using Biocotek water portable DO analyzer, model number JPB – 607A. Water pH and Electric Conductivity were analyzed using JENWAY portable pH and conductivity meter, model number 430 while the titrimetric method was used in analyzing water hardness. The mean value of water temperature for Structured Water (SW) and Unstructured water (UW) was 270C, pH value was 6.96 for SW and 7.51 for UW. Dissolved Oxygen had a mean value of 9.8mg/L in SW and 7.5mg/L in UW. Mean value of electrical conductivity was 62μЅ in SW and 98.8μЅ in UW while water hardness recorded a value of 24mg/L in SW and 80mg/L in UW. The mean value for BOD was 3.8mg/L in SW and 6.2mg/L in UW. Bacterial growth was investigated using MacConkey Agar (MAC) and Eosin Methylene Blue Agar (EMB). The initial analyses for MAC and EMB recorded no growth of bacteria, which meant their absence. In the final analysis of MAC, Catfish (Clarias gariepinus) reared in UW showed bacterial growth with pinkred colour while poor growth of bacteria was recorded in fish reared in SW. In EMB, the final analysis of the fish sample reared in SW showed Mucoid pink and Colorless colonies, an indication of organism fermenting neither Lactose nor sucrose while in UW, colonies appeared purple – black showing bacterial growth in the gut of the fish. This result indicates the repulsive nature of structured water (SW) to harmful germs in the living cells of an organism which helps to maintain a healthy environment within the cell.

Key words: Physico-chemical Parameters, Bacterial Growth (K), Structured and Unstructured water