Originally Posted by jlk
Carbon really isnt necessary in an aquarium in general unless you are trying to remove meds. Are you throwing away your carbon filters every few weeks? By doing this, you are throwing away all of your beneficial bacteria that has grown on your filter & probably risking a mini-cycle. Yes, you can use the old filter from your tank to help seed the new tank but you should also consider switching to a more permanent type of filter media (sponges, foam, polyfill) rather than wasting money on carbon replacements every few weeks & disposing of your good bacteria. Hope this helps!
Agree that carbon isn't necessary, but it sounds like the OP has an Aqua Clear filter where the carbon is a separate insert from sponge and ceramic media.
@ the OP- Yes, you can use your carbon insert to seed your new tank. I run my Aqua Clears with 2 sponges stacked on top of one another, and the Bio Max insert on top.