You could ride with the tight chain and take it easy. The chain will loosen up.
Actually, I'd install a chain tensioner. I'm making one right now for my Staton gear chain setup from a skateboard wheel I bought at a garage sale for $5. Everything should hang well with a spring,scrap metal and nut/bolt.
A tensioner would work well for almost any chain-driven machine. It places less tension on the system and allows you to change to different size sprockets without adjusting the chain or adding or subtracting links.