I have no coraline algae on my rocks

[cshenderson]

My reef tank is roughly 7 months old and I have no coraline algae growing on the rocks. Well, virtually no coraline algae on the rocks. The back glass is covered with pink coraline, but so far the rocks are more white than pink or purple. I use hamilton 125w 10k with PC atinic blues. Any thoughts?

 

[Pandora]

Where are your calcium levels at? This is the major determinant for coraline, not lights.

 

[TekCat]

The fact that you have coralline algea growth on glass is a good sign. As Pandora said, check calcium. Also Alkalinity is important. What do you have as far as Phosphate goes? PO4 inhibit calcification, so that could also be a problem.
Coralline likes moderate lighting. And had been reported that it likes 420nm actinic alot (I could be wrong here). Water flow is another factor.

 

[JaMan]

I have also found that magnesium is also important to its' growth.

 

[cshenderson]

My mag and calcium levels are in check, and my PO4 is fine. I have a fuge with Cheato, which has been great. I do not have one stand of bad algae (crossed fingers) in my tank. I feel like things are in balance becoase I am geeting coraline growth on the glass. Why would it not be on the rocks too?

 

[Syon]

is it possible that the lights are bleaching the rocks? i've found that a product called Aragamilk causes corraline to grow like crazy in my tank.

 

[capefear]

try some purple-up.

 

[tbettis]

purple up. get some

 

[TekCat]

I am far from being an expert. Having said that, could it be that there is a bacterial or algal film of some sort covering rock's surface that inhibits coralline growth? I would find a "test" area on the rock (maybe an inch in diameter) and scrub it lightly with a toothbrush to remove whatever is on the surface. Then check on that spot from time to time.