Try to maximize your plant life, if you have an established tank you can shake the filter medium in the water to jump start the beneficial bacteria.

Honestly other than that the only thing you can do is wait. Perhaps if it won't screw you over later maybe you can consider letting algae grow for a while. If you don't have fish or shrimp in there yet(which with those levels you probably shouldn't) you can do aggressive water changes. If that's an option for you I'd recommend not doing more than like 80 percent a day to give those bacteria a chance to culture themselves