I have a hob topfin75 on my 55 gallon(adding another 30 hob after I finish painting the background) currently it just has the sponge and the filter bags (w prebagged carbon ) I am clueless as to what other filter media to get to replace the bags and how to add it? Also what order...any detailed help would be greatly appreciated. I cant seem to wrap my head around the different types of materials and what works the best. (Also how often to change/clean it all)
