Goblin Acropora RTN/STN?

[Blackice615]

Hey guys,

I'm trying to determine if this coral, that I believe to be the Green Goblin acro is starting to RTN or STN? It's been this way for the past month or two and the browning has been moving up slowly.

I've had it for three months. Added Radion XR30's two months ago. Slowly ramped up over 6 week period.

Salinity is 1.026
Nitrates 2
Phosphate 0.03 - 0.08
Alk 8.5
Calcium 420
Mag 1480

I previously had Mag a little higher (1700) due to over dosing 3-6 months prior to getting this coral and simply let it work it's way down. Nitrates were at 0, however I removed the purigen that I had in for two weeks.

I'm inclined to believe it's just losing color at the base due to shading and no receiving light at the lower end. There are a decent amount of growth tips towards the top.

 

[Blackice615]

Another angle

 

[vetteguy53081]

Looks like result from shading. Very hard to avoid based on other rock and inhabitants in tank that are utilizing surrounding light

 

[Blackice615]

Thank you, I appreciate the response.

Lastly, will it ultimately kill off the whole coral or just the bottom look like this? Theres still great polyp extension down there.

 

[jsvand5]

If it were me I’d cut it off up to where it starts branching and glue it to a new plug. It doesn’t look like it’s ever going to encrust the way it is now and I think it will eventually break off the plug at the base when the coral gets bigger. As a bonus, you’d end up with another frag because the current “stalk” would regain color. You’d need to acclimate it to your lights though since it won’t be used to getting full light.

 

[vetteguy53081]

Thank you, I appreciate the response.

Lastly, will it ultimately kill off the whole coral or just the bottom look like this? Theres still great polyp extension down there.

I have a couple that are like that and doing just fine with the meatless base. Wont kill off coral and as long as remainder is getting light, it will thrive.

 

[Epic Aquaculture]

It appears to be an Anacropora, not an Acropora. They are notoriously slow encrusters (if they ever encrust). Honestly it looks fine to me. You could cut it off an re-glue if you want, but it most likely will still not encrust any time soon.

 

[seamonster]

If you dont want to cut it, make sure theres ample water flow at the base. Its awesome that you still have polyp extension too; that marns its not dead, its just due to shading that it has lost color. It might still encrust over too in order to get more light.... good luck [emoji41][emoji106]

Feed your tank too (reefroids, copepods, etc) so corals get food too. Very important for the shaded areas of the corals in our reefs and of course, the ocean. Cutting it is also an option too. Happy reefing!!

 

[Blackice615]

Thank you for the posts and clarification. I feed reef roids once or twice a week also. I have cut another coral similar to this one in the past 6 months and the same thing happened pretty much but it didn't look nearly as bad as this one. Helpful to know moving forward

 

[rkpetersen]

Another thought would be to add more diffuse lighting like some T5s to your LEDs, which will result in fewer severely shaded areas.

 

[Blackice615]

Thanks I didn't think about that

 

[rkpetersen]

Thanks I didn't think about that

I did so recently on two tanks, using the AL hybrid fixture. Very happy with the results. :)

 

[Blackice615]

I read about of all the success with t5 setups. I'll research them a little further and see if it's a viable option