Table acro bleaching

[coqui1pr]

Hi there i've had a table acro coral now for about 4 months now it was doing great not until today when i came home today to see that the middle section of my table acro was bleached dont know why i havent done anything out of the ordinary all of my parameters are inline no temp swings all of my other corals are doing excelent just a question of why some corals behave like that here are my water parameters

Alk 7.8 dkh
MG 1440 ppm
CA 430 ppm
PH 8.2
PO4 0.0 ppm(salifert,seachem no hanna)
NO3 <2 ppm
Silicate 0.0 ppm
SG 1.024 stable
Temp 78-79 stable

None of my fishes bother any of the corals nor any predators or plagues are bothering the corals my photoperiod is actinic is on for 12 hours a day and the MH is on for 7 hours a day im using a giesseman megachrome 13k bulb 250 watt,i've been using zeo for 8 months now and running stable my zeo dosing is as follows

Start2 1 drop 1x per week
Bak/food 1x per week
AAHC 3x's per week 1 drop
PIF 2 drops 2x's per week
K-Balance .5 ml 2x's per week with PIF dosing
FE 1 drop 2x's per week
CV 4 drops each day

Thanks
Nestor

[The man]

Maybe a flow issue or ya have a bad crab in there eating on it.
I found the same thing to a millie it had a big white patch, Later on thet night i cought the culprit. A gorrilla crab was munching on it.

[coqui1pr]

I dont have any crabs in my tank and the flow inside my tank is about 600 to 700 gph(my tank is a 30 gal tank)it gets random flow around the colony.

Nestor

[gqjeff]

Yea I would look at flow issues also.. Def does not look like AEFW damage which is a good thing. Also you should be dosing start2 daily as part of the system.

Jeff

[coqui1pr]

Thanks jeff but if i dose start2 daily i get the brown film in my panes and sand.

Nestor

[gqjeff]

Nestor, possible check your MH bulb to see if the envelope around it has a crack in it.. I doubt that is the issue but worth looking into. I would def do a drop of start2 3-4x weekly as its a carbon food source for the bacteria..

Jeff

[The man]

You may have good flow, But inside the acro it could be non existant.
Typical flow patterns dont really go down that low in a tank with sand, and seeing that you dont have a sand storm there leads me to believe that the flow is lower at the bottom. Try moving it to an area that has better flow.

[coqui1pr]

Im going to try and place it somewhere else but the funny thing is that the sun coral below the table acro when the lights go out and it opens up for feeding at night all of the sun coral polyps move and swing to the flow of water thru it even the back polyps but i will try that anyway and jeff i checked the bulb there is no crack i didnt thought of that thanks.Here is a full tank pic sry for the crapy shot.

Nestor

[gqjeff]

Nestor, I am heading out for the night but wanted to see if you possible have changed your flow pattern lately. If you have direct flow on the coral it can lead to recession also.. Have a nice evening and hope you get it figured out.

Jeff

[coqui1pr]

No i havent changed it in a while jeff it has been like that for the past 8 months now.

Nestor

[mesocosm]

Greetings All !

Hi there i've had a table acro coral now for about 4 months now it was doing great not until today when i came home today to see that the middle section of my table acro was bleached dont know why i havent done anything out of the ordinary all of my parameters are inline no temp swings all of my other corals are doing excelent ...

While I agree with others that flow and lighting are potential issues, particularly as a table acro colony matures ... the picture says "predator damage" to me. Hitch-hikers are often difficult to "catch in the act" as they are typically noctural. Also, their presence may take several months to become known, since they oftentimes enter our systems in a larval stage, and require time to mature to the point that they become problematic.

If it's not a crustacean predator, perhaps it's a vertebrate. What other fish are present in the system? Any one that may have developed a taste for tissue ... like another Centropyge (Dwarf) angel, for example? (I saw the ones pictured ... you wouldn't think that the pygmy angel, yellow tang, or chromis would be a problem). Any gobies that like to hang out in the acro? Some species will "strip" sections of an acro to prepare a nesting site.

Also ... is the denuded area expanding, or remaining constant? Are there any other smaller areas exhibiting the same problem? In the picture, the area looked pretty discreet/"contained". From the picture, the affected area looked pretty "clean" ... is/was there any evidence of dead tissue or organic debris in the area?

The only other thing that leaps to mind is physical trama ... anything fall on, or get blown up into that area recently. Just a thought ... good luck.


HTH

[coqui1pr]

Well i havent seen any of the fishes doing anything to any of the corals that i have,i only have a pygmy angel,yellow tang and three blue/green chromis the pygmy angel is well behaved he hasnt nipped at any of my corals so far

(the moment that he does it he's out)and for nocturnal predators i havent seen any the reason that i know this is that i work at home and my work is done at night i repair computers and i stay up late(up to 6am local time) and

i have the tank right here where i repair the computers and watch over the tank all night long last night the tissue where it bleached was kind of light in color and then when i came to see the tank today it was as the picture that

i posted really weird im breaking my mind with this i tested the tank for everything and came within zeo requirements there is always something interesting about this hobby.It hasnt bleached anymore it stopped there so far.

Thanks
Nestor

[Aged Salt]

Hi Nestor, as you know Acro-tables are the most sensitive of the Acroporids to element imbalance. The STN here can be from too high a Mg level. Try to settle in ~1250-1300. Bob