Unfortunatley no one has mentioned lighting as a factor for coraline growth. One would have a very hard time growing much coraline under just 6500k Iwasaki lights no matter what your alk or calcium levels are.

Strong actinic spectrum, dim lighting or very blue spectrum lights are nessecary.

cheers

I don't agree with that notion anymore, I am growing coraline like crazy with high PAR levels than a iwasaki 250 watt. even with my ABs that were out dooing some iwasaki 400 watt setups I still got good coraline growth. I just put the 14K bulbs back in the tank so now I will see if I get even more growth (which would support the theory a little)

I now belive that you might not get the same color of coraline but you will still get coraline if your main conditions are right. befor the move I have green, light purple, blue and pink coraline on the rocks but only pink and light purple on the glass. sence I totaly scraped out the tank when I moved I now have light purple starting on the glass again and the other colors going nuts on the rocks.

Steve

don't forget that Idea was old when I started looking into building a reef tank and I decided it wasn't worth not having a skimmer.

Steve

Well Steve, For the past 2 years on my 90g, lit with Iwasaki's. I could never get corraline to grow. I was running a reactor, levels were good. Put corraline covered rock's into the tank and the corraline would dissappear.

Now with the 230. I have Lot's of light over the tank but I ditched the Iwasaki's. I now have the radiums (400w) times 2 and sun aquatics 10K (250w) times 2. My corraline is starting to show up. It's not a deep purple but more of a light pink.

Anyway, I want to change the 10k bulbs to a more blue bulb soon. At that point I bet I can expect more corraline to show up.