Aquaculture, Fragging

Fragging Corals for Beginners

You bought a coral frag from your LFS a few months ago. It’s beautiful, but starting to grow too close to your acans. What can you do? Frag it! Fragging, which is the process of taking a larger colony and cutting it into smaller pieces or fragments, is a fun way to keep your tank happy and healthy. Of course, the bonus is having extra frags to trade with other hobbyists.

A frag of Hawaiian Ding Dang zoanthids
A frag of Hawaiian Ding Dang zoanthids

What Should I Frag?

The first step to fragging is figuring out what you are going to frag. A good rule of thumb is to cut off no more than 1/3 of a mother colony. You want to make sure that you have enough left of the mother colony to place back in the tank so that it can grow. Another rule of thumb is to make sure that you are only cutting corals that are healthy. If you have a colony of zoas that will not open, for example, it is most important to figure out how to remedy that issue. Cutting up stressed out corals can cause them to recede or die.


Now that you have chosen which corals to frag, you need to collect the proper materials to ensure success. It is time to determine what cutting implements you will need. If you are going to frag SPS, you can use metal cutters to break off pieces from the mother colony. For soft corals, like mushrooms, a clean, new razor blade will suffice. A Dremel can be helpful when you need to cut through a ceramic plug, but be cognizant of the heat that the Dremel produces with friction so as not to damage the flesh of the coral. A tile saw is an effective way to cut through ceramic plugs and rock or through hard skeleton, but they are expensive and often only owned by professionals.

ME Coral Gel is thick and viscous, perfect for fragging
ME Coral Gel is thick and viscous, perfect for fragging

Just Glue It

The next step after selecting your cutting implements is to select your glue and plugs/tiles. The best glue to use is cyanoacrylate gel, better known as superglue. We recommend and use ME Coral Gel. The important aspect here is that you use gel. The typical superglue that is most commonly sold is not a gel and will not command a firm grip on your coral fragment. Once you have purchased glue, it’s on to plugs/tiles. For a fast growing coral, like zoas or cyphastreas, large plugs or tiles will provide you with the most surface area to allow your coral room to grow. For slower growing corals or SPS, smaller plugs will suffice.

Plugs of this size would be great for SPS
Plugs of this size would be great for SPS

Tips and Tricks

So you selected the corals you want to frag, you have cutters, glue, and plugs- you are ready to roll! Some rules of thumb when fragging:
  1. There are certain corals that don’t frag well. Stay away from fragging plates, elegance, or lobos. Corals that do not have smaller, easily cut polyps or branches, such as these, are best left alone.
  2. Some corals are prone to infection, such as goniopora, when fragged. Dip each frag in iodine after cutting to reduce chance of infection and death.
  3. When fragging mushrooms, do not glue them down. They need to attach themselves naturally to rock or rubble. Put the mushroom frags in a mushroom box or plastic box with a screen on the top in your tank and the mushroom will naturally attach to rubble rock over time, which you can then glue to a rock or a frag plug.
  4. Make sure you use protection! Make sure to use gloves and a face mask when fragging. Many corals can sting and fragging can cause small particulates to enter the air that can be harmful to you and your pets. Be most cautious when cutting zoas and palys as they contain palytoxin and can cause flu like symptoms or even death if ingested or touched.

Now that your frag tank is full, you can sit back and enjoy your tank.

What is your favorite type of coral to frag? Have an interesting fragging story? Let us know in the comments below!

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