accomplished by soaking the membranes with 40 g citric acid for4 h, 0.5% hypochlorite for 8 h, and then 20 g of citric acid for 3 h.In the production period before the first chemical cleaning, theconcentrate was diluted with 30 L fresh seawater on a daily basis.From then on the concentrate was completely replaced with freshseawater one time per day