Nanotechnology is emerging as a rapidly growing field with its application in Science and Technology. Silver nanoparticles have proved to be most effective as it has good antimicrobial efficacy against bacteria, viruses and other eukaryotic micro-organisms. Unfortunately attention to potentials of this new technology in aquaculture industry is unheard. In this study indirect use of silver nanoparticles was investigated for reduction of eggs fungal infections during incubation period of Rainbow trout (Oncorhynchus mykiss). Nanosilver-coated Clinoptilolite was compared with unmodified Clinoptilolite as filter media in two separate recirculation systems. Whole water of each incubator was circulated through out the filter media and again backed to incubator. In baskets of each incubator 2000 newly fertilized eggs were put. The water of each incubator was infected by introduction of water mould-infected eggs periodically. Water temperature and chemistry were routinely monitored and maintained constant over the entire incubation period. Dead and infected eggs and embryos were periodically removed and survival rates were expressed as percentages of the initial number of eggs used for fertilization. To confirm valid coating of silver nanoparticles on Clinoptilolite properties of coated materials were investigated using FTIR, XRD, XRF, and SEM methods. Percentages of survival from fertilization to eyed-stage in nanosilver-coated and uncoated Clinoptilolite were 60.42 and 67.20 respectively. Also hatching rates was 56.33% and 60.39% respectively. Percentage of survival from hatching to swim up stage was 96.94 and 97.99 respectively. Totally, percentages of survival from fertilization to swim up stage were 54.60 and 59.17 in nanosilver-coated and uncoated Clinoptilolite respectively. No fungal infections were observed during incubation period in incubators which have nanosilver-coated filters. The percentage of malformations of produced fish wasn’t significantly differing betw
