Bugs in Filter
 

Hi,I noticed these front 4 legged bugs/worms about 3/8'' long crawling
around inside my homemade bio-filter. Are these a good thing or not so good
thing. I made a three stage down flow filter consisting of a course filter
media then to a fine filter media and then to the bio-media made up of of a
combination of lava rocks,clean stone and bio-nuggets.I also intalled a
splash plate to help oxygenate the water as it came in. Any help would be a
great help. Thanks in advance....