just squeeze out some of the filter junk from your current tanks filter into your new tanks filter.. and make sure you have something to "feed it" I usually go w/ a pinch of flake food or a few pellets. I just swish it in a bucket of water when I do filter maintence and dump the sludge/water into the new tank. or if you have loose bio-media toss some of that into your new filter ( works even better)... or run your new filter alongside your other tanks filter for a week or two to "prime it" then put it on your new tank and just keep the tank fed with either fish food or ammonia.
The bacteria that perform biologic filtration are of the genus Nitrosomonas and Nitrobactor, are sessile, meaning they require a surface to live on such as gravel, tank walls etc.
Old water does nothing.