The objective of this study was to evaluate the suitability of pumice stones, volcanic tuff and greenhouse shading net as alternative pad materials to the widely used and commercial one called CELdek. For this purpose, the tests were carried out at four levels of air velocity (0-6, 1-0, 1.3 and 1.6 ms(-1)) four levels of water flow rate (1.0, 1-25, 1.5 and 1.75 l min(-1)) and three levels of pad thickness (50, 100 and 150 mm). The tests were made at 30 +/- 1 degrees C and 40 +/- 1% relative humidity air conditions. The temperature of water flow was kept constant at 25 +/- 2 degrees C during the tests. According to the results of this study, it can be stated that the volcanic tuff pads are good alternatives to the CELdek pads at 0.6 m s(-1) air velocity. (c) 2007 IAgrE. All rights reserved Published by Elsevier Ltd.