And I ' m the Duchess of York Really , though you were most likely downvoted cause you claimed to be smart enough to know more than the average person on this topic and then said you couldn ' t be bothered with it . <| sep |> Hey , sent a trade offer ! <| sep |> There ' s no need imo , your sponges should take care of any gunk that comes from the tank , if there ' s any need for it , you clean that in tank water and leave the sponges . One thing at a time basically . The black one might be more porous , but I ' m not familiar with it . The more surface area , the better basically since the bacteria has more places to go . Where the other foam might be more dense to block out the gunk from your tank , I just run filter floss to be honest and I ' m fine . How to tell is when ammonia and nitrites are still 0 after a couple of days and nitrates go up . At that point , you ' re doing water changes to keep nitrates low