I bought my 150g used off craigslist. It was a reef tank before. I went through a ton of razor blades scraping off the coraline algae. It'll be a little work, but between razor blades and vinegar, you'll be able to get it nice and clean.
"What, exactly, is the internet? Basically it is a global network exchanging digitized data in such a way that any computer, anywhere, that is equipped with a device called a 'modem', can make a noise like a duck choking on a kazoo." - Dave Barry