HOT Magnum Canister Filters HOT (Hang On Tank) Magnum is an efficient, powerful, compact canister filter that is lightweight enough to hang directly on the back of your aquarium. Because it is a Magnum, it comes feature-packed with the ability to convert with ease from a continuous duty mechanical and chemical utility filter to a water polishing filter with micron filtration capability. Comes complete with a Carbon/Media Container and Water Polishing Micron Cartridge.