A method for cleaning a film separating device involves: a) performing positive-direction water cleaning when the ratio between the film filter resistance and the preliminary film filter resistance is less than 1. Further, the present invention provides methods of treating a disease characterized by undesirable levels of nitric oxide. A first type of module makes it possible to perform a manual configuration of the Add-Drop channels and the coupled WDM channel while a second type of module makes it possible to carry out remote configuration. In yet another form of the invention, shaft projections into the mixing chamber comprise a tooth having a substantially reticulated face forming a deflecting surface such that substantially all mixing chamber particles encountering the tooth strike and are deflected at an incident substantially lateral angle from the deflecting surface.