Hi everyone, I’m pretty new to this. I’ve just started a 29 gallon tank with two bloated belly mollies. I plan to add more slowly. My question is what is the best way to change filter systems without loosing all the bacteria in my current filter. I currently have a TopFin filter assembly that has the replaceable filters and they say to replace monthly. I’ve read this is not a good idea and want to change to a different filter system (probably the kind with the sponges and replaceable media or whatever is the most recommended) Any recommendations on good filters for a 30 gallon tank? Also what is the best way to change over to the new filter system without loosing all the bacteria? I just don’t like the idea of constantly having to replace filters and loosing all bacteria. Feel like there has to be a better system out there. Thank you and glad to be a part of the forum!