Dan Swenson, West Los Angeles, CA Dan, good news, you don't need to have a lot of money nor lighting to grow coralline algae. One thing you should be aware of is that there are many different species of coralline algae. Some require vast amounts of light while others are perfectly happy in low lit systems and will in fact die-off if given too much light. If you got a fresh piece of live rock only a few days to weeks from the ocean this should not be a problem but if it came from an established system with high lighting, you may not have received spores of low light species. However, the biggest problem may not be your live rock source but your water chemistry.
Coralline algae require sufficient calcium and bicarbonates in order to grow.
I would suggest you test these parameters and see if they are at acceptable levels. Beware of liquid calcium solutions as these usually consist of calcium chloride only. Using this will increase your calcium but will also lower your alkalinity, putting you into a see-saw battle of adding alkalinity booster to combat adding the calcium additive. The other element found to be used by coralline algae during calcification is strontium. If you are not doing so already, you should be adding a strontium chloride supplement to your aquarium.