©Association for Aquatic Sciences of Nigeria (ISSN: 0189-8779) http//www.journalofaquaticsciences.com 295 Journal of Aquatic Sciences 29 (2A): 295-308 (2014) ASSESSMENT OF CRUSHED WATER HYACINTH (Eichhornia crassipes) AS ORGANIC BUFFER FOR FISH PRODUCTION IN PORT HARCOURT, NIGERIA O. A. DAVIES 1 AND E. T. JAJA 2 1. Department of Fisheries and Aquatic Environment, Rivers State University of Science and Technology, Port Harcourt, Nigeria 2. Department of Applied and Environmental Biology, Rivers State University of Science and Technology, Port Harcourt, Nigeria Correspondence should be addressed to O.A. Davies: daviesonome@yahoo.com ABSTRACT A preliminary study was conducted to evaluate and compare organic buffering capacity of crushed water hyacinth and calcium carbonate on acidic borehole water for aquaculture. Thirty, 25-litre shaded plastic tanks (20-litre filled with experimental water, pH 3.0) of three replicates per treatment of 180 g buffer agent were used. Treatments (T) were: control (C)[T1], wet whole plant (WWP)[T2], wet roots (WR)[T3], wet stem (WS)[T4], wet leaves (WL)[T5], dried whole plant (DWP)[T6], dried roots (DR)[T7], dried stem (DS)[T8], dried leaves (DL)[T9] and calcium carbonate (CA)[T10]. Temperature and pH were monitored once daily while dissolved oxygen, calcium and alkalinity were measured once a week for seventeen days using standard methods. Data were analyzed for analysis of variance and descriptive statistics using Microsoft Excel. pH values of T3 (6.7±0.22 ) and T6 (6.8±0.22 ) to T10 (7.2±0.22 ) on Day 17 were not significant (P>0.05) and within the range of 6.5-9.0 acceptable for fish production. DWP, DR, DS and DL competed favourably with buffering efficiency of CA. This study recommends use of at least 180 g of DWP, DR, DS and DL for treatment of 20 litres of acidic water for minimum of fourteen days for aquaculture. It is economical and safe for fish production and human consumption. Key Words: Organic fish farming, organic buffer, potency, pH, water hyacinth INTRODUCTION Water pH is an important water quality parameter for aquaculture. Water quality is a very vital factor as good feed and feeding in fish production. Bad or poor quality of water tends to increase stress on the cultured animals, reduce their growths, make them susceptible to diseases and lead to mortality. A sound insight of the physico- chemical and biological parameters of water is highly necessary for successful fish farming. To large extent, water determines the success or failure of an aquaculture operation. Water quality management is important but expense (Estim, 2009). High acidity or alkalinity can cause direct physical damage to skin, gills and eyes. Prolonged exposure to sub-lethal pH level can cause stress, increase mucus production and encourage epithelial hyperplasia with sometimes fatal consequences. The quantity of hydrogen ions (H + ) in water will