mushroom coral

How to Frag Your First Coral

Do you keep soft corals in your aquarium? Have you ever bought a coral frag from your local fish store, or a fellow hobbyist and wondered just how exactly they did it? Have you thought about fragging coral in your aquarium, but weren’t sure where to start?


This article is written to show you how to have success fragging coral for your saltwater aquarium.

Very simply, coral fragging is the process of cutting, breaking, or otherwise sub-dividing a coral colony. While it may seem harsh to break apart a corals, you should know that they are genetically programmed to survive and even flourish in these conditions. I’ve written about it before—

Even newly formed coral embryos successfully grew after being fragmented in a laboratory experiment. Plan and simple—reproducing and growing via fragmentation is in their DNA. The coral does the hard part—(healing, settling, reorganizing and growing), all you do is assist with the fragmentation. LPS corals are a good choice for fragging because it is fairly easy to break apart the branching varieties, but overall it takes intermediate skill to keep some LPS. Because of that, I’m going to make a slightly different recommendation for the beginner.

If this is your first time fragging a coral, one of the easiest specimens to start with belong to the group of corals commonly called ‘mushroom corals’. These guys grow on rocks as an individual, large, fleshy polyp. They routinely ‘frag’ themselves either by splitting (a process where the polyp forms two mouths and eventually splits itself down the middle) or by budding, where a piece of the foot of the mushroom pinches off and forms a new polyp.

In my experience, just about any sliver of a mushroom coral can and will reproduce a new polyp, no matter where it is cut from, and no matter how small. That is why I recommend these corals as a first –choice for fragging.

Mushroom Coral: Rhodactis sp.

Mushroom Coral

One note of caution—you should never try to frag newly purchased corals. You should let them acclimate to your aquarium conditions for a couple months, undisturbed before trying this. Once you feel certain the coral is growing well, you are ready to begin.


  • 1 brand new razor blade
  • 1 small bowl
  • 1 piece of live rock rubble or other substrates to attach your frag to
  • 1 small patch of plastic mesh (from a bag of fruit, or wedding veil material from a fabric store, etc.)
  • 1 rubber band

underwater coral

Step 1: Pull out the entire rock that the coral is attached to. You don’t want to frag the coral in your tank if you don’t have to. It’s best to pull the rock out. The rock will be wet—very wet, so make sure you place it in a bowl or on a stack of paper towels to minimize the mess

Step 2: Take the razor blade and slice off a piece of the mushroom coral. As I mentioned before, almost any piece will do. My preferred ‘method’ if you can call it that, is to try and cut the entire cap off of the mushroom coral—by using the razor blade to slice horizontally across the stalk, leaving the foot (the part of the coral stuck to the rock) behind.

Step 3: Fill the small bowl with aquarium water and drop the piece of the mushroom in—you’ll likely see some white stringy material hanging from the fresh-cut fragment, and you’ll see some brown stuff ooze out.

Step 4: After a very brief dip in the bath, take the fresh-cutting out of the water, place it on the live rock rubble (outside of the bowl) and dump the fouled water.

Step 5: Wrap the live rock rubble up with the plastic mesh and hold in place with the rubber band

Step 6: Gently place the rubble in an area of your tank with low flow and return the rock with your mother colony back to its original location in your tank.

Step 7: Wait…this is the second hardest part.

Step 8: After some time, you will notice that the damaged stalk will grow a new discoid-shaped head, and the piece of coral you cut free will naturally attach to the live rock.

Step 9: Once your frag has settled and attached to the rock, you can safely remove the plastic mesh and glue the rubble to the final location in your aquarium.

Congratulations. You have successfully fragged your first coral. It’s really that easy.  Now, trade that frag with a fellow hobbyist and share this article with them, so they can do the same thing.

If you like this and want to learn more about how to frag corals, I wrote a book all about it, titled…you guessed it…How to Frag Corals. Check it out.

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