I dont know if I'm the only one, but whenever I would refill my 2 Little Fishies phosban reactor I would have a hard time keeping the media from going into the central tube. I tried their recommendation with scotch tape but that never worked especially since the media was wet from being rinsed. :scratchch Then I hit on an idea - use one of my Salifert test kit tubes and invert it over the reactor tube! It worked wonderfully. Now if only I could figure out an easy way of centering all the pieces perfectly when I want to put it back together.