Im hoping to pick up a 180l tank this week rather than the 125... (arghh am I mad?) Anyways, I have a 80l tank right now (big jump)and of course I will have to cycle the newer tank. Since its an existing tank and has a fully mature filter (1 years old) I was hoping to transfer around 60% of current water from my tank and then adding RO water from my friends place to cycle the water and get it to to correct temp. How long should I be cycling this for? Would it be beneficial to bring as much water in the 180 tank water? My current fishes will benefit from a 40% water change tonight, but I was wondering. If I fill up the new tank with my "water change" each day will this suffice? I wont be siphoning any of the muck, just pure water transfer. Is this advisable? Im just hoping to cycle the tank as quick as I can and allow the fishes a bigger home to play with. I know I must be patient and might have to wait anything up to 2 months depending on water parameters so anything that can cut this time will be more pleasing as then I can sell my current tank and recouperate some money back.