ID please

[marleesan]

blob:https%3A//mail.google.com/6506572b-0251-43c5-9fd5-c3890c021ba4

I have a 20 gallon long that has been set up for about 4 months. I recently added corals, and noticed a weird brown substance, not the algae, on the sand bed. What is this? Is is the mushroom coral?

 

[Dkuhlmann]

You can't post pictures from your email to this server. You will have to download it to your computer in a file and then you can post it.