i dont know if you've already tried this, but what i've always done when i set up a new tank is to 1- dechlorinate the water and let it settle 2- take out the media from an up and running filter and just dunk it a few times in the new tank and 'shake' out some of the bacteria in there 3- plug your new filter and let it run 1 or 2 days. and voila! running tank
of course you can't put a ton of fish on the get go but you get the idea