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Saltwater Aquarium/crystal like circles on live rock.


White Dots
White Dots  

White Dots2
White Dots2  
Hi David! I started a 10 gallon nano tank. The tank was set up a while ago and a week and a half ago i put some live rock in. There are small white crystal like circles showing up on the live rock in various locations and i did some research and cant find if the are harmful or what they are. the are almost flat to the rock not like an egg. Other than these dots there are no other "hitchhikers" that i have seen at all. Any ideas? THANKS SO MUCH! I really appreciate the help and cant wait to hear back! photo is attached -Meredith

Hi Meredith:

There are many marine organisms that can come in on live rock, so many, that some are not even classified as of yet. However from the images that you've provided they look like white flowering polyps, which do come in on live rock as hitchhikers / stow-a-ways. They are completely harmless and make a welcome addition to any coral reef aquarium.

Thank you for the question.

I wish you much success with all your future saltwater aquarium endeavors.

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David Ocreef


Technical saltwater coral reef related aquarium questions are welcome. Coral, invertebrate, and peaceful species of saltwater fish questions are welcome. Questions asked on Saturday and Sunday will be answered the following Monday. REMINDER: Please check the answers pool to see if your question has already been asked and answered. Questions typically are answered within a 48 hour period, however sometimes it may take longer.


I possess over twenty-five years of hands-on experience and knowledge in the ecology of aquariums. Beyond the traditional, I have successfully tested and sustained environments that have been uncharted territories for hobbyists, for decades. I am the first to admit I don't know it all because there will always be something new, amazing, and exciting to learn about, as discoveries are made. It's a hobby one can never outgrow, or grow tired of.

MASNA - Marine Aquarium Society of North America. Director of Orange County Reef Aquatics -

Publications,, and many others.

After High School, my experience and love of marine animals influenced me to take up studies in Marine Biology. Throughout college, I studied Microbiology with an emphasis on Marine Life, as well as numerous other sciences. I continued to advance in this hobby, by building a dozen or more saltwater ecosystems all utilizing Microbes as the major source of my filtration method.

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