How to evaluate a replacement filter equivalent to the one you're using now. For any number of reasons, you’re looking for a new filter supplier. If your current filtration performance is satisfactory, replacing the filters with the correct equivalent will do. But if you need to improve filter performance, a different configuration of your current filter or a different type of filter will be the solution. Either way, a quality supplier should take the time to determine exactly what equivalent means to you, and help you identify the appropriate filter(s).