[Myka]

I doubt it's green coralline algae for many reasons, but mostly because your tank is new. My guess is exactly what Marie said...but got a pic??

You've already jumped the gun by adding a cleanup crew too early. SLOW DOWN! You're going to get yourself into costly trouble. Remember, nothing good ever happens fast in a reef aquarium.

You have no need for a calcium test kit until you start adding corals or if your pH drops. As suggested, spend the money and buy quality calcium, alkalinity, and magnesium test kits when the time comes. Cheap ones are inaccurate, and aren't worth the cardboard they're packaged in. Try Elos or Salifert.