Sun Coral Fragging, Part 2

Why, when, how to and how not to

3. How to frag sun coral:

Take a look at PawsReef's illustrated thread about fragging tubastrea colony at the stage, when it should be done (not overdue, like mine).

In more difficult case, some planning is required:

1. The smaller part should be separated from the main mass. By pulling or prying from the sea squirt.
2. Then place it with stony surface facing the bottom (no live tissue there, it will take all the impact).
3. Chisel should be placed in the middle, between polyps.
4. One hammer blow, with some luck, and done - two pieces are ready for gluing to the pieces of rock.
5. The bigger part is done in the same fashion, where the line of natural growth makes it reasonable to divide.

Sounds simple.
Let's see the practice vs. theory, or How not to do it.

4. How not to frag:

Have fun.

1. Be prepared to deal with planula, instead of parent colony:

Like:
1 - not tipping over floating vessel in the sump, that temporary holds the planula (or the coral),
2 - have the 800 micron filter mesh bag nearby - for straining planula into it, and then putting it in the sump, until this attempt of fagging is over,
3 - putting the coral back an the tank, and deal with planula.
Anyway, have a plan for this emergency.

Daniela Stettler (see her pdf file) used syringes to collect the planula, for placing it on prepared ahead artificial surfaces with creases. It's a pity, that no more information on process was shared with other keepers through the web, at least I wasn't able to find it through the search engines.

2. If the tubastrea colony is attached to the living organism (sea squirt, in my case) - do not try to pull them apart: it is impossible, and an applied force - no matter how gentle - will kill the polyps under fingers:

The good part is, that they started to get overgrown by live tissue after two weeks.

3. I had read about good results after using the rotary tool (like Dremel) with diamond saw.

I had disastrous results:

• the depth of cut is (at maximum) less than a half of the blade diameter, 9 mm, or 3/8".
• Inserting screwdriver in the gap does not help to crack the main mass of skeleton - and couldn't be: it only ~1/6 of the total thickness.
• Even worse - trying to do the second cut on the opposite side - through the live tissue. It becomes torn apart, but has no effect on skeleton dividing:

Eventually had to finish with chisel and hammer, and ended with a lot of small pieces.

Result on the next day: even with frequent removing of the grey necrotic tissue from these frags, they look not good:

They will survive - the central polyps opened to eat, but not good for the tank too.
Well, you see my point. Looking back, it was rather obvious.

5. What worked the best:

1. What worked better for separating from sea squirt:
Using metal cutter and scissors, trying to undercut between colony and sea squirt. This pushes them apart, and not cuts the squirt.

2. For breaking apart the skeleton, chisel and hammer: in direction from the top to the bottom, starting from the polyps side. Cleaner break:

Here is what you could see inside, the cross-section of sun coral after a clean chisel break. And why 9mm deep Dremel diamond blade cut did not help much: 1" (2.54 cm) marble tile for comparison:

Already glued frag, with the place to grow on:

Why using the marble tiles - on the next page.