Persimmon said:
The problem here is that it not a well colonized wheel and she has no other bio in the filter system. She has only been over using the charcoal inserts. If the wheel was highly colonized or she had other media, yes, I think it would work for the bigger tank too, but from what I saw, there is no good bacteria goo build up on that wheel.
Jeeny, the wheel looks clean, have you been washing it and if so, how?
Is the hex cycled? If it is, then she has an adequate colony for this purpose. It's not going to colonize more than enough to support the fish that are in the hex regardless of how much floss and noodles you stick in it. Seriously.
From the pictures she posted it's fine. With a bio wheel you really don't need all that stuff you have in yours, persimmon, really. And the bio wheel does not have to look "gooey" at all. I rinse mine out in the tank water. Not the old tank water, the tank water. Gooey wheels do not turn well.
Jenny, do NOT wash that filter pad in tap water. Transfer everything over the to 20g. Rinse out the filter pad in the tank water in the hex. Get the mulm off it, but don't wash it too much. There's good bacteria in there. Don't wash the bio wheel either. If it gets really gooey, rinse it out in the good tank water. That way bacteria that come off stay in the tank.
Put the whole thing in the 20g and let it run. Don't change out that filter cartridge until it totally falls apart, then just substitute a sponge or if you want, a new cartridge. Carbon really doesn't do a heck of a lot, however, so it's pointless. I still use cartridges, however, only because it's easier for me.
Roan