Vinegar will clean it up, but you don't want to get any into the tank water and you have to rinse it really well. I only use vinegar when I'm breaking a tank down.
I usually take anything that has it on it (hood, filter, light, etc) over to my sink and clean it there with plain water. Most times I can use something to gently scrape it off (my thumbnail). The more difficult stuff I'll use an old toothbrush and plain old water.