interesting observation

[T Diddy]

I've had some issues with a few corals losing color after having lived in my tank for sometime. Recently, I had a small rock fall on one of my montis. After I finally removed the rock (a week or more later) the affected area looked dead white from lack of light. The new growth that took its place is as colorful as ever. In fact all new growth around the perimeter is colorful. The established tissue in the middle of the coral is browned out.

Am I correct to assume that my lights are not bright enough? It seems that the colors are washed out as a result of too many zooxanthellae.

 

[Reef264]

Depends.What lighting are you running.It may be a Water chemistry issue.

 

[gon08]

Not sure what you are asking here but I'll give it a shot.
The coral that was covered lost it's color because it wasn't getting any light. Once uncovered the new tissue grew with it's normal coloration because it's new growth has nothing to do with the stressed tissue. The stressed tissue is turning brown because it is repopulating the zooxanthellae it lost while being shaded. Once the coral reestablishes the zooxanthellae to normal levels it will begin to regain it's color also. I'm not sure why you would think your lighting is inadequate if the coral looked good before being covered and the new growth looks good.

 

[T Diddy]

Depends.What lighting are you running.It may be a Water chemistry issue.

I was leaning towards lighting because of good color and browned out color both on the same coral. to answer your question, there are (4) T5s and 24 Cree LEDs on a tank that is 30" tall.

Not sure what you are asking here but I'll give it a shot.
The coral that was covered lost it's color because it wasn't getting any light. Once uncovered the new tissue grew with it's normal coloration because it's new growth has nothing to do with the stressed tissue. The stressed tissue is turning brown because it is repopulating the zooxanthellae it lost while being shaded. Once the coral reestablishes the zooxanthellae to normal levels it will begin to regain it's color also. I'm not sure why you would think your lighting is inadequate if the coral looked good before being covered and the new growth looks good.

gon08, I suppose I should have posted a pic. The entire coral was browned out except for the new growth at the perimeter. The shaded area that turned white was browned out prior to the rockfall. Now I remove the rock and the new growth is beautiful, but will be brown again soon I'm sure. That's why I considered too little light and too much zooxanthellae. Any thoughts?

 

[gon08]

gon08, I suppose I should have posted a pic. The entire coral was browned out except for the new growth at the perimeter. The shaded area that turned white was browned out prior to the rockfall. Now I remove the rock and the new growth is beautiful, but will be brown again soon I'm sure. That's why I considered too little light and too much zooxanthellae. Any thoughts?

Unfortunately I am not very knowledgeable when it comes to LED's. My experience with others that do run them is that they can easily bleach corals. It may be that you have too much light with the LEDs. I would like to see pics of the tank as well as the affected coral and some others in the tank. Also what are your parameters.

 

[T Diddy]

Tank parameters are as follows:

Salinity- 34ppt or ~1.025ish
Ca- 420
KH- ~8
Mg- 1300 ? I don't trust my test kit :uhoh3:
NH3- undetectable
NO2- undetectable
NO3- undetectable
PO4- undetectable

I honestly think that the lighting is less than stellar when it comes to intensity. The T5 ballasts are struggling to power the ATI bulbs, and I am not running the LEDs at full power either...plus there are only 24 of them. I'm stumped.



Anyway, here is a relatively recent tank shot. I'll have to post a pic of the coral in question later.

 

[T Diddy]

OK here are a few shots with and without flash. Notice the white piece of rubble I placed next to the affected area. That area was covered, then when shade was removed it grew in with blue polyps just like the new growth around the edges of the coral. As you can see, the entire coral has browned out except for this area and around the edges. The entire thing was covered in beautiful blue polyps when I got it.