and take it out of your tank. it might be good to have a bucket to put it in since it’s wet. remove the filter cabinet and expose the filter matter. rinse the filter matter under water of room temperature until the water that runs from it is almost clear. you should not try to get it completely clean since you want some bacteria to remain in it when you’re done. when you’re finished with the filter matter you should rinse the rest of the filter. this includes removing the top of the filter and rinsing the engine if this is possible on your filter, which is the case for 