why does the coralline cover my glass faster than my rock

[Phyto]

Does anyone know why coralline algae grows much faster on glass than on the calcium rich live rock? It does so in my tank anyway.

[AnimaliA]

Murphy's Law? Sorry, I don't know, but I am interested in hearing the answer also

[ckoral]

great question. The answer is... um... um...


later in this thread. I am taging along

[norskfisk]

Just a theory: The glass is rubbed clean so it is a good surface to settle on. The rocks are covered with thick bio film so the algea "spores" get eaten, covered or somehow outcompeted by the faster growing softer organisms.

[conformity]

although my tank has only been running for 7mo, i have noticed my coraline is opposite from what you are experiancing. i have green coraline that has established on the back wall of my tank but reds and purples have yet to grow in any noticable density there or the glass alike. my rock was almost completely oxidized/ bleach white when i got it. now the majority of the serface area has been coverd in new coaline , mostly purples and reds.

[jmanrow]

Originally posted by norskfisk
Just a theory: The glass is rubbed clean so it is a good surface to settle on. The rocks are covered with thick bio film so the algea "spores" get eaten, covered or somehow outcompeted by the faster growing softer organisms.

Makes sense since the coralline grows much faster on the front glass than the back and side glass, which rarely get cleaned.
The solution must be to scrub your rocks...

[piercho]

The pink coraline which covers the glass or acrylic quickly is a specific specie, I'm sorry but I don't have the reference at hand. It is the same one that is seen on Ventricaria bubble algae vesicals. IMO its a pioneer specie suited to colonize clean, smooth surfaces, but never dominant for real estate otherwise. When my tank was less than a year old it use to build up on the back glass in sheets and fall off in sheets when it got too heavy to support it's own weight. That's when I ran total alkalinity at 3.0 meq/L and higher. At lower alkalinity like 1.5-2.0 meq/L it is not very competetive, IME.

[piercho]

faster on glass than on the calcium rich live rock?

Specifically, the glass is clean surface and this specie of coraline is a fast colonizer. The rock may be full of calcium carbonate, but its not available for the algae to make use of. The algae has to pull calcium, carbonate and magnesium as ions from the water column.