Formalin, a solution of 37% formaldehyde (Van Waters and Rogers, 1988), is effective in treating Saprolegnia (Fitzpatrick et al., 1995; Mitchell and Collins, 1997; and others), and is the only fungicide registered for use in aquaculture in the United States (Bruno and Wood, 1999; Marking et al., 1994; and others). However, there are concerns about its affect on both the environment and personnel who handle it (Fitzpatrick et al., 1995; and others).
Hydrogen peroxide is a promising chemical for the treatment of Saprolegnia (Fitzpatrick et al., 1995; Marking et al., 1994; and others) with minimal impact to the environmental (Bruno and Wood, 1999; Mitchell and Collins, 1997). However, it is important to consider the species, life stage and water temperature when treating Saprolegnia with hydrogen peroxide (Rach et al., 1997).
Sodium chloride at high concentrations, i.e., sea water at 29 gm/liter and salt water at 15 gm/liter, is lethal to Saprolegnia (Marking et al., 1994; Pickering, 1994), and effective for controlling S. parasitica (Willoughby, 1994).
ANY LUCK YET??