Help with cutting back SPS coral

Laith · Nov 11, 2022

I'm having difficulty finding the best way to cut back one of my SPS coral colonies. It has become huge, about 80cm end to end and 60cm front to back. The coral is home to a school of eight chromis which I've had now for at least four years. It is now hitting the surface of the water and really starting to cause problems with any potential corals I would want to place on the same rock underneath due to shadowing.

Here is a picture of the coral in question:

The picture isn't great but the dark area below the growth is the same coral structure but that has died due to a lack of light... this is normal and I've seen similar in various reefs I've dived on.

However, I need to cut it back, but how? I've trimmed the top and edges multiple times but I want to lower the entire coral back onto the rock. To do that I would have to get rid of the dark dead structure. But because it's a branching SPS structure I can't just cut the top live part off, remove the dead part underneath and re-attach the live part to the rock. If I cut the top part off I just end up with a hundred frags!

Anyone with experience doing this?

This coral started with a frag about the size of my finger so of course I could start it all again the same way: cut it all away and then attach one frag back to the rock.

But then the chromis no longer have a home and I firmly believe that the reason I have been able to keep the same size school of chromis for so long with no losses is that they have this haven. I have many times seen chromis in the wild that live in the same type of SPS and always use it as a haven to dart into if threatened.

So, anybody with experience with this type of "trimming" situation? How would you approach this?

All and any suggestions very welcome!

Nano sapiens · Nov 11, 2022

That's a good sized coral colony!

While not nearly that large, I have a Seriatopora that I have to cut back ever few years due to the dense growth shading corals underneath. I remove the whole colony and then cut off a number of the best branching structures (5-6 pieces). I then reattach them securely to the same spot and let it regrow.

Any alterations to the colony are not going to make your Chromis happy, but at least this way they'll have some structure to feel somewhat safe in until the newly mounted pieces grow out to form a larger size again.

mermaid_life · Nov 11, 2022

That is quite impressive!

Not personal experience, but if I was in your shoes, I would get some smaller pieces of rock and glue larger fragged pieces to each rock and temporarily glue them all together to simulate the larger colony. Then I would remove each colony as it grew and keep cycling new rocks with frags.

Laith · Nov 11, 2022

Nano sapiens said:
That's a good sized coral colony!

While not nearly that large, I have a Seriatopora that I have to cut back ever few years due to the dense growth shading corals underneath. I remove the whole colony and then cut off a number of the best branching structures (5-6 pieces). I then reattach them securely to the same spot and let it regrow.

Any alterations to the colony are not going to make your Chromis happy, but at least this way they'll have some structure to feel somewhat safe in until the newly mounted pieces grow out to form a larger size again.

That's actually a great idea... why didn't I think of that?

I could take the entire colony out and then frag six or seven of the branching areas that would still form a structure (as opposed to just a thumb sized frag). If I re-attach those to the rock bunched together I think it would still be a good habitat for the chromis...

This may be the only way to go about it.

Thanks!

Laith · Nov 11, 2022

mermaid_life said:
That is quite impressive!

Not personal experience, but if I was in your shoes, I would get some smaller pieces of rock and glue larger fragged pieces to each rock and temporarily glue them all together to simulate the larger colony. Then I would remove each colony as it grew and keep cycling new rocks with frags.

That's also a good idea... but I think I can get the same result just by removing the entire colony and then re-attaching selected branching structures close together on the original rock the colony started on.

But attaching the larger frags to individual rocks might give more flexibility... interesting!

mermaid_life · Nov 11, 2022

Laith said:
That's also a good idea... but I think I can get the same result just by removing the entire colony and then re-attaching selected branching structures close together on the original rock the colony started on.

But attaching the larger frags to individual rocks might give more flexibility... interesting!

Yeah same concept. I was just thinking about ease of maintenance in the future.

I just cut up some colonies. It is a bit of a chore. Those colonies are surprisingly HEAVY.

Laith · Nov 11, 2022

mermaid_life said:
...

I just cut up some colonies. It is a bit of a chore. Those colonies are surprisingly HEAVY.

Yes... and of course much heavier to lift when you get them out of the water

. Especially when you're leaning over a 90cm deep tank when you're pulling one out

.

But for me these "problems" are worth it (my back doesn't always agree!). So grateful that I had the opportunity, funds, space and wife support to be able to have a large tank!

Laith · Nov 12, 2022

Just for reference, the coral colony I'm talking about was initially a frag attached to the top of the middle pile of rocks in this pic. Keep in mind that the tank is 90cm deep top to bottom...