Low Light Coralline?
 

What's the lowest lighting you've had coralline algae grow well under? By well, I mean covering at least 75% of the rock.

Does the inside of my skimmer count? It's lit with 2 26w power compacts that are about 3 feet away and yes there is at least 75% coverage on the side of the skimmer facing the lights

I have a 25G tall SPS tank and it is growing Coraline algae under 2 x 55W PC bulbs.

Tom R

13 watt in a eclipse 12. took almost three years though lol

I have a 50 gal and coraline grows right to the bottom. 3x 27 watt home depot daylight CFLs. They only have the 25 watters now.

I have deep purple coralline growing on rocks in my sump that get the spill of 2-400w halides at over 6' high and 3' away.

I thought so!! Thanks guys! :)

I've never been able to figure out why my tank doesn't grow coralline. I figured I could rule out lighting. The tank is 2 or 3 years old (can't remember), and there are only small patches of coralline. It's always been that way. It's an LPS reef, so obviously cal, alk, mag are all in check. I just can't figure it out...

Pour in some purple up, that should fix it! (kidding!)

But maybe?

Next time I scrape mine off the glass I'll save ya some shavings.

Thanks Starry, but I don't think that will work! There IS coralline in my tank from day one on the rocks, and it does grow on the glass too, but I mean I have to scrap the glass like once every couple months, and I'm only getting quarter-sized patches in that time MAX. My rocks are freakin WHITE for the most part.