Why has my water filter made my water less clean?
No filter removes all contaminants.  Carbon is great for improving the taste. The white ones remove large sediment. Activated alumina removes some fluoride among other things. Distilled water will be free of most things but volatile chemicals will make it through. UV light and micropores (ceramic and "nano tubes") will remove most virus bacteria protozoa and cysts. Uv light will kill most if not all of those little nasties if the flow is right.

So the first step would be to go get your unfiltered water tested. Then see what's in it that concerns you then figure out what you need to remove those contaminants. Your filter might not be designed to remove the stuff you have a problem with.