Black slime

I'm in the process of changing my filters on the FS 300 system. When I pulled out the old filters , there's like a black slimy substance on the tops of the 3 filters (mostly on the middle 2nd and and white tops), and it does smell a bit like mold or mildew. I'm concerned this is on the permanent connectors, and want to know if it's harmful, or how do I clean it?  I didn't find this question in the forum.

Also, this is the 2nd year I've had the filter, and we have hard water where I live. Is that a problem for the large, black permanent filter, or any of the filters for that matter?

3replies Oldest first
  • Oldest first
  • Newest first
  • Active threads
  • Popular
Like Follow
  • Status Answered
  • 5 mths agoLast active
  • 3Replies
  • 115Views
  • 2 Following