I'm going to be upgrading my 60 gallon to 75. I have a couple of questions. I want to cycle as quickly as possible and keep cost to a minimum. I plan on using most of the equipment from the 60 gallon, if i moved over my filter(s) how long will the tank take to cycle? I think the only thing i'm going to be replacing is the substrate. I would keep what I have already and just add to it but I don't want to stress out my fish anymore then I need to. If i do replace the substrate, how many pounds for a 75 gallon? If I don't replace it, I'm not sure if I want to go sand or gravel, but i'm trying to be as cost efficient as possible. When I'm filling up the new tank, should I use the water from the 60 or not worry about that?