What is killing my Blue & Purple Acros ?

[Stormtrooper]

Hi all from Western Australia.

I have a problem with some of my cultured Acropora's that I cannot
work out so I thought I would see if I can get some expert advice.

My system has been running for 16 months and during that time I have
had really good rates of growth and it would be fair to say it has all been
thriving.
However, over the last couple of months I have run in to a problem
that I cant get to the bottom off and I need some "expert"
guidance.

What is happening is that most of my blue & purple (*A.microphthalma,A.abrolhosensis,A.tortuosa A.vaughani)
colonies/frags are showing symptons of some disease that basically
causes the coral tissue to waste away from the tip of the axial coralite and eventually kill the coral.

The first sign is the axial coralite polyp expels a white mucuos like
thread (mesentrial filaments) and the polyp appears to die at that stage.

Over a week or so the tissue slowly breaks down and the polyp is dead.

This gradually spreads down the coral eventually wiping it out but not like
RTN as the majority of the tissue remains albeit with the colours
faded.

Upon examination of the dead piece the coral tip basically crumbles in to a brown paste when you crush it and it is very brittle.

I do not believe it is a parasite,worm,snail etc.

I have dipped a couple of pieces that were showing early symptons
of the disease in to a melafix solution and there was no sign of
anything living.

Now the technical details are as follows.

System Size 2000 l(1800x1200x400) plus DSB, Refugium & Sump
Lighting 3 x 250w MH and 3- 4 hours per day natural sun light.
Water Movement 10 Tunze 6100's & wavebox.
DSB
Fuge with ECO Reef Base
I only use natural salt water and change
approx 10% per fortnight

My readings are as follows:-
SG 1.026
PH 7.8 - 8.2
Calc 420 (using digital probe)
KH 8
Mg 1300
PO4 0.04 (using digital meter)
Nitrates - 0 (salifert test kit).

I have various other Acros such as A.Busheyensis,Vaughani,Millepora,
Sarmentosa, that are not affected
however others are browning out whereas others are perfectly fine.

Now comes the twist, six weeks ago I ran some Seachem Reefmatrix
Activated Carbon through a FBF. The flow rate was sufficient for the
granules to bubble in the reactor chamber but no more.
Over the first weeks I noticed that the corals were getting covered by carbon particles
and my Skimmer was going crazy extracting large amounts of black "mud".

At this point I put a 10 micron filter sock over the outlet of the FBF
and it had to be cleaned every day of a black liquid soot.

I finally took it out two weeks ago and I am still removing black soot from the system.
I certainly dont think this helped any of the corals and it may be responsible
for the browning out but the original problem had arisen prior to this.

The weird thing is it definitely affects the blue & purple acros only (at this stage maybe).

I have wondered if there is something that is needed to produce the blue/purple pigment that may be lacking, if such a thing exists !.

I will post some photo's once I get the camera of my Daughter.

Obviously I am keen to hear your opinions/questions etc as I have run out of ideas.

It has been recommended that Iodide should be dosed however I have never
used this so I am a bit reluctant to start.
I did previously "feed" my SPS with a home made coral food however I have
phased this out a few months ago, again based on advice that it is not necessary so possibly this has had an impact but why only certain corals are affected does not make sense.

Sorry for such a long post and thanks for taking the time to read it all.

Here is a photo of the set up

Thanks

David

 

[Stormtrooper]

Over 100 views and nothing, what a bummer

 

[Logzor]

That is a very frustrating situation. Definitely give people some more time, you may have just stumped everyone!

I take it that your other acropora are doing fine, meaning no tissue or color loss. As for your blue and purple acros, did they show any signs of stress, loss of color or polyp extension before the tissue necrosis.

I think the biggest clue is that the tips become brittle, perhaps an issue with alkalinity or pH?

I know you probably have done this already but build a list of things to rule out and work it out from there.

My first guess would be alkalinity issue, there was a bad batch of Salifert Dkh kits, based on my own experience, and those on RC (search the thread in the Reef Chemistry section). Could you try another brand kit? You make the problems with your carbon sound like the most obvious explanation, definitely consult the people in the Reef Chemistry section, maybe there is a strong correlation.

Other than that I am not sure, have there been new additions where some sort of pathogen could have been introduced?

 

[Stormtrooper]

Thanks Logzor for replying.

I do use a Salifert KH test kit however I have tested my tank water against natural sea
water and the results were almost identical which makes me think it is OK.

It is almost like the tips are being burnt.

I dont think the carbon helped but as previously mentioned this problem was starting
prior.

Could it be a lack of food/nutrients causing the corals to starve ?

My ph fluctuates from a low of 8.0(am) to 8.3(pm).

I am going to perform a 50% water change today and keep monitoring.

I have had others suggest "White Band Disease" but the symptons do not appear
to be the same.

Thanks again & merry Xmas.

David

 

[dan223]

Ive had the same thing going on with my purple tort:sad2:. Ive looked very closely for any bugs and connot find any, the tips look burnt or somthing and and the polyps have filiment looking strands coming out of them. Some of the tissue on the tips comes off and surrounding tissue turns white. Ive been leaving it alone and it seems to be regrowing and looking better the last couple weeks. I posted a similar thread and only 1 other person replied and said he was experiencing the same thing. Ive checked many many times with lights out to make sure nothing was on it and have been stumped. All my parameters are good, sg 1.025, alk 9.5, cal550, mag1450. My photoperiod 7.5 hrs, I may start uping it just to see what happens.

 

[FelipeRB]

i just can suppose reasons and try to correct it to try to stop that, i´m not a expert.

i see you have a mixed tank, i had read that some LPS mucus affect some acros, and you can use activated carbon to reduce that! i don´t know if it is real.

 

[LifeAquatic]

Assuming you have good stable parameters and no pest. Have you always run carbon in your tank? Or was it a recent addition? Im probably wrong but when I run carbon I notice two things happen. The water gets much clearer and sometimes the coral loose a little color. I have a suspicion there are two problems happening at once. One, the water is becoming clear so fast the corals dont have time to adjust to the intense light and the tips burn. Try running your lights 1 hr less per day for a week and see if that helps. Also, carbon is good at polishing the water. Almost to good.. It pulls out the bad and good nutrients. You might be starving your corals a little. Try your feeding schedule again with the carbon to see. Also, leaching carbon into the tank cant be good for the corals. Some corals might be over seneitive to the carbon dust.

 

[aurora]

Do you use carbon on a regular basis? The burnt tips could be the result of a sudden increase in light intensity from carbon clarification of your water. We tend to put our blue/purples on the very top and they are the most susceptible to sudden light changes. If you don't run carbon regularly, running a large batch of carbon through the system can significantly increase light to your coral due to improved water clarity especially if you haven't run carbon for a while.

 

[aurora]

Ooops...looks like LifeAqua beats me to it....

 

[Dionae]

Stormtrooper,

Burnt tips usually is the result of alkalinity issues. However, since you are using natural salt water and all your parameters seems in check, I would suspect that the lack of growth on the tips indicates that you have too little nitrogen in the water. This is especially true if you are using carbon (which is very effective at stripping away nutrients) and not feeding the corals.

For an experiment, stop using your carbon and squirt some food on your coral, and observe your growth over a 2-3 week period to see if there are any changes. By the process of elimination, you can see if this is a nutrient issue, water chemistry issue, or disease.

Good Luck,
Dionae

 

[Canarygirl]

I had a similar mishap with carbon in a reactor shooting out into my filter sock (on the outlet from the reactor), but enough carbon dust went through the filter sock that I saw corals starting to turn gray from the carbon dust. Skimmer was also pulling out black stuff, and some pink sponges turned dark gray. I lost a lot of corals after this event. The ones that didn't turn gray and die, lightened up a whole lot and have not had any polyp extension since this time. I am babying them and hoping they don't die but it's not looking good.

I hope you have better luck than I've had. I'm going to stick with using carbon passively in a filter bag from now on.

 

[Stormtrooper]

Ive had the same thing going on with my purple tort:sad2:. Ive looked very closely for any bugs and connot find any, the tips look burnt or somthing and and the polyps have filiment looking strands coming out of them. Some of the tissue on the tips comes off and surrounding tissue turns white.

.

Thanks for the responses.

Dan those symptons are identical to what has been going on with my system.

I have now done the following.

1.Did a 500 litre water change last week and another one today.
2.I have replaced my Aqua Medic Shorty II Skimmer with a new SWC300A
Skimmer from Reef Filtration and the water clarity and discharge from the
Skimmer are significantly better.
3.I have taken every coral frag plug out of the system and removed the
carbon particles with a tooth brush ! plus scrubbed all the egg crate to
remove the carbon sediment build up.
4.I have recommenced regular feeding with my home made "mix".

Apparently the symptons are consistent with a Nitrate spike however
two different test kits showed Nitrates to be in the vicinity of 0.1 - 0.5 which
I regard as low.

I have no doubt the carbon particles have aggravated the Acro's and
caused them to brown out/die.
Over the last few days things seem to have improved with less recession
and some hints of colour returning.

I do not use Carbon on a regular basis and after this episode I will be reluctant to ever use it again.

Thanks for the input:wave:

David