I've been considering setting up a maternity tank and have a couple questions that I haven't found answers to while doing research. I was going to buy a 10 or 20 gallon with a filter (duh), heater, and one piece of deco. I will fill the tank with water from my tank the first time and use media from the main tank in the filter. When it's unoccupied and I don't have a holding female do I still keep water in the tank and perform weekly water changes? I guess I'm confused as to how the bacteria colony will remain alive during periods where there aren't any fish in there.