Just recieved the last shipment of equipment for my 75. I want to set it up right now, but am planning to be away for about a month later this summer. I've decided to leave the tank empty for now, and then a few days before I go, put in the sand and water and let the tank cycle for a month while I'm gone. my question, will the tank still cycle with just the filter running, do the bacteria require a certain temperature?