D daffer New Member Joined Aug 28, 2006 Messages 14 Reaction score 0 Dec 2, 2006 #1 Hi I have a eheim 2215 with coarse blue filter pads and want to replace some of the pads with substrate but to avoid killing of bacteria how much should I replace should I do it in stages? and what is the best substrate to use.
Hi I have a eheim 2215 with coarse blue filter pads and want to replace some of the pads with substrate but to avoid killing of bacteria how much should I replace should I do it in stages? and what is the best substrate to use.
