I agree with Ryan and Adrienne, you need to keep changing the water until it is clear.
Carbon will not be able to effectively absorb much yeast. Similarly, alcohol will only adsorb to carbon with a weak bond so that won't be very effective either. At any rate, if the carbon has been in your filter for a month or more, it will be 'spent' and unable to absorb much more.
There is usually no need to use carbon under normal circumstances. You would mainly use it to absorb excess medication after a treatment or if you have added other chemicals to your tank. As Adrienne said, it is best to remove spent carbon since it may start to release absorbed chemicals back into the water.