I agree with d3rryc's method.
You don't need to dose your tank with anything other than calcium. You will need a rock or rubble with coraline already growing on it. If you have a friend with a reef tank and if they have a thermometer in the tank with coraline all over it, ask if you can borrow it and use a razor blade and scrape the coraline off the thermometer and into your tank and you'll see significant increase. When you spread the smaller pieces all over the tank they tend to grow quicker in my experience.