I have a Penguin 300 and a HOT Magnum filter in a 55 Gal
fresh water tank. I try to do water change once a week up to two week max. I usually wash the type C filter in the syphoned water and change it every two months. I have been running carbon in the Magnum.
I have been trying to figure out the best set up. I've read a lot that you don't need a lot of carbon in the system and it doesn't last long so it gets expensive. The Penguin type C filter has the carbon media in it so that will be changed regularly. I was thinking I don't need the carbon in the Magnum, but not sure what other media would be good to run. I was also thinking of using the media bin in the Penguin but again not sure what to use. The water balance has been fine and clarity hasn't been an issue. I tend to get matter in the filters regualry. My pelco loves to kick up gunk which is fine as it sends it into the filters. Thus why I was thinking of running some extra media in the bin to catch the particles being sucked up into the Penguin.
If it matters I have the a Pleco, a Gourami, a dwarf Gourami, 2 Tetra Neons, a Guppie, a snail, and a Striped Barb.