Ok. I have a 20 gallon tank that has had fish in it since early March. Everyone's been doing well, water quality's been good. I just got a new 20g tank. To cycle it, I was thinking about taking the carbon filter out of the filter that is in the current tank (HOB Whisper 20) and putting it in the new filter in the new tank to establish a population of beneficial bacteria. Is that a good idea, and if I do that, how long should I wait before adding fish? I am planning on maybe cardinal tetras, cories, and a dwarf gourami for the new tank. And a shrimp.