Yes, charcoal is technically a chemical filter. Not everyone uses charcoal
either.
A biological filter is a necessity for an aquarium. There are many
different types (bio-wheels, filter pad, canister, undergravel, etc.) The
principle point of a biofilter is to use nitro-bacteria to convert the toxic
compounds of ammonia and nitrite to the non-toxic nitrate.

Check out information on the Nitrogen cycle for aquariums or information
about "cycling" you tank.

Justin

"robbins876" wrote in message
oups.com...
I have a charcoal filter that that came with my 10 gallon tank
starter-kit. I've been reading up on biological filtration. Am I
correct in the fact that charcoal filters are not the same as bio
filters? Since I don't have a bio filter, how imperative is it that I
get one? IS charcoal just a chemical filter?

Thanks,
Rob