Need help identifying this

[MR2MAS]

Looking to see if anyone can tell me what this is...

When i built my tank, I used some seeded clamshells I got from addictivereefkeeping.com to help with spreading coralline as early as possible since i'm using dry rock during the cycling process.

I just finished my cycle last month. Since then, I've only added 2 clownfish and some low budget coral to see how my tank is doing. I haven't seen much algea growth anywhere in the tank with the exception of my clamshells. It's a brownish color that rubs off fairly easy. I can't tell what it is. It's only growing on my clamshells and not anywhere else. I'm debating if I should just toss these things out.

Any help would be appreciated. Thank you!

 

[Timfish]

My guess would be some kind of cyano. It may be predominately on your clam shells but your tank is inoculated now so I'd leave them in if youlike the looks of the shells. Cyano is one of the "uglies" that occur during the maturing process so even if you toss the shells you're still going to have to deal with it sooner or later. Since they are introducing beneficial stuff (a lot that can't be cultured and stuck in a bottle) I'd not only leave it but add some maricultured or wild live rock. See Aquabiomics article on establicing healthy microbiomes. I'd also recommend FOrest ROhwer's "Coral Reefs in the Microbial Seas".

Establishing a Healthy Microbiome in a New Aquarium Using Live Rock

Studying the effects of live rock in a newly established aquarium shows that high-quality live rock promotes the rapid establishment of an effective biological filter and a microbial community similar to those found in mature reef tanks.

www.reef2reef.com

Here's some videos you may find informative:

"Coral Reefs in the Microbial Seas"

Changing Seas - Mysterious Microbes

Nitrogen cycling in hte coral holobiont

BActeria and Sponges

Maintenance of Coral Reef Health (refferences at the end)

Optical Feedback Loop in Colorful Coral Bleaching

Richard Ross What's up with phosphate"