For info on what a UV
unit does check our articles area please. We have a few good UV
articles in there. As far as if a skimmer can be added to the lifeguard modular filtration my guess would be no. You could add it but its not going to be enclosed like the rest of the modules and if you do end up adding it then you will most likly end up adding it to a sump. Their are three basic styles of skimmers. You have the ones that go inside the tank, the ones that hang on the back of the tank and then the ones that sit in a sump. The later two can easily be placed in/on a sump.