Hi, I just purchased a 55 gallon tank and now it is time to cycle it. I was wondering if I could put some of the old water from my 29 gallon tank (and gravel) into the tank and if that would work? But don't I need some sort of ammonia source? Thanks! Any suggestons would be great because this is my 3rd time cycling a new tank (10,29 and now 55)!