Thanks for that. I have been running the tank now for about 3 weeks but with christmas and all I have not found out if I have it set up right - A bit slack I know, but the fish seemed happy so I didn't worry. (I had been doing water changes etc though)
The noodles are not really underwater so does that mean the bacteria on them is dead and that is causing my tank to get dirty???
I guess all will be revealed when someone can help me with the specifics of my tank.
I don't think the sponge has ever been rinsed!!