Why do you need new things to fill it? Unless your using some fine polishing pads that are clogged. If not just take it apart and clean the sponges in a bucket of discarded tank water by giving them some good squeezes and rinse. Clean the biomedia with a swish and rinse with discarded tank water as well. If your using carbon, throw it away and get some more bio media and fill the canister with it. Don't need to replace anything until it is falling apart, which will take years. You need to know what kind of canister you have to know where to get replacement parts. Walmart may have some bio media if you need more. If not LFS will have some.