I have a filter cartridge in my aqueon 10 hob filter (the one that comes in the 10 gal kit) and I think I will need to change it soon. I've had it in there a while and its just time to change it. I know it has a lot of bacteria in it and i'm supposed to seed the next one but I don't know how to do that because a second cartridge won't fit in the filter. There is a second filter element sponge in there that must have a lot in it, as well as all the gravel and ornaments etc so will there be enough to bacteria to just change the filter or is there some better way to seed the new one? Thanks.