Put another filter on there. I had a Penguin filter die on me. Very scary. Luckily, everything survived. Canisters are wonderful for planted tanks. I use a fluidized bed filter. I think it's neat and it has plenty of surface area, but it lacks a compartments to put peat and things.
Leave both filters on your tank for at least a month. I stirred up my substrate and washed all the media in my existing filter in tank water so that it would get sucked into the new filter several times. This allowed my bacterial population to establish in the new filter. If you can, remove some of the media from your dying filter slowly so that the new filter bears most of the filtration burden. Later you can put that media back in the dying filter for backup. As a side note, dying filters can usually be healed with a full disassembly and cleaning.
Brandon
Equipment Nerd
"I keep water. Fish and plants just make my job harder."
