Carbon does make a good home for bacteria, so you could just leave it, but then you lose some bacteria if you have to take it out, to medicate for instance.
It's just wasting money; replace it with more 'normal' media; sponge or noodles, whatever fits in your filter best.
It's just wasting money; replace it with more 'normal' media; sponge or noodles, whatever fits in your filter best.