The Bubble Magus Media Reactor Mini 100 has been developed by Bubble Magus to produce a robust, well engineered and affordable reactor for fluidising a whole range of filter materials used in marine and freshwater aquaria. It is a small self-contained media reactor designed to be used in a sump. The pump is located in the base of the reactor and the water is pumped up through the media and leaves the reactor through the top and returns back into the sump. The reactor is supplied with an upper and lower perforated plate along with a fine mesh pads to stop all but the finest media particles from exiting the reactor in normal use. When using Bio Pellets in the reactor the upper pad should not be used as the perforated plate will prevent the media from being flushed out of the reactor. Finally, the reactor is simple to fill and empty the media, as there is no central stand-pipe, and it also features a simple ‘base release mechanism’ that allows easy access to the bottom of the reactor, a feature often missing in reactors costing two or three times as much. Please note: this reactor has to be used in a sump as the water leaving the reactor does so under gravity. It cannot be used outside of an aquarium or sump. perfect for use with: Phosphate removers bio pellets activated carbon Biological sand as a fluidised bed sand filter.