Dark spots on corals?

bskipper · 03/10/2014, 10:51 PM

Hi there, I've been reef keeping for a good ten years now. In my 125 mixed reef/fish I have a variety of corals and a few fish and rose anemones. My corals are: frogspawn (lots), lg toadstool, torch, star polyps, zoas, mushrooms, lg brain coral, Kenya, galaxea, jasmine, green nepthea, sun coral. Most recently added were the small colony of jasmine, nepthea, galaxea, brain. The rest have been in there for 2 or more years.

I noticed my sun coral had some dark spots on the outside (not flesh, only on skeletal areas) last night, and today I can see some on my frogspawn as well. We recently changed all bulbs in my coralife fixture, and did cut back the time on by 4 hours. The new lights are 3 new 150watt 14k pheonix (as were previous bulbs) and the actinics are sunpaq 420/460s. Could the bulb change be causing the spots? Corals are extending out and doing well. It's the only change I've done, aside frome feeding a new frozen food of omega one oyster eggs to my anemones,etc. otherwise I feed (and always have) frozen emerald entree, marine cuisine, PE Mysis, new life spectrum pellet, nori (have tangs).

Tank specs all in normal range.

Are these dark spots a sign of them dying? I once had a nepthea die of what I thought was black spot, but not sure this is the same thing. What else could be causing it? Any thoughts are greatly appreciated. Thank you!!

bskipper · 03/10/2014, 10:58 PM

my sun coral isn't out as much as usual. The one with the largest spot on it is not out at all yet, where normally they are all out full by now. :-(

bskipper · 03/10/2014, 11:56 PM

Ok, on closer inspection with only moonlights on and using a flashlight up close while corals are mostly in, I see it on about 50% of the frogspawn, and it's on the white 'flesh' that comes way down over the hard skeleton. It looks like reddish/brown dots, almost like freckles (lol) and they wipe off very easily. I'm thinking this is not the same black stuff that killed my nepthea a year or two ago. However, I think what is on my sun coral skeleton may be different. It seems hard and crusty, darker brown/black in color and does not scrape off so well. I was able to see some coming off when I tried scraping it, but it doesn't completely come off. Only one of the three is coming out tonight, which is very unusual. I've had this sun coral, which has grown significantly, for almost two years. Any thoughts? I've turned on my UV, which I don't run on a 'normal' basis. I can cut back on the light times more, if that seems to be the culprit. I've replaced bulbs before, but not usually all at once like this time. They were all overdue.

03/10/2014, 10:51 PM	#1
bskipper Registered Member Join Date: Feb 2004 Location: PA Posts: 64	Dark spots on corals? Hi there, I've been reef keeping for a good ten years now. In my 125 mixed reef/fish I have a variety of corals and a few fish and rose anemones. My corals are: frogspawn (lots), lg toadstool, torch, star polyps, zoas, mushrooms, lg brain coral, Kenya, galaxea, jasmine, green nepthea, sun coral. Most recently added were the small colony of jasmine, nepthea, galaxea, brain. The rest have been in there for 2 or more years. I noticed my sun coral had some dark spots on the outside (not flesh, only on skeletal areas) last night, and today I can see some on my frogspawn as well. We recently changed all bulbs in my coralife fixture, and did cut back the time on by 4 hours. The new lights are 3 new 150watt 14k pheonix (as were previous bulbs) and the actinics are sunpaq 420/460s. Could the bulb change be causing the spots? Corals are extending out and doing well. It's the only change I've done, aside frome feeding a new frozen food of omega one oyster eggs to my anemones,etc. otherwise I feed (and always have) frozen emerald entree, marine cuisine, PE Mysis, new life spectrum pellet, nori (have tangs). Tank specs all in normal range. Are these dark spots a sign of them dying? I once had a nepthea die of what I thought was black spot, but not sure this is the same thing. What else could be causing it? Any thoughts are greatly appreciated. Thank you!! Last edited by bskipper; 03/10/2014 at 10:59 PM.

03/10/2014, 10:58 PM	#2
bskipper Registered Member Join Date: Feb 2004 Location: PA Posts: 64	my sun coral isn't out as much as usual. The one with the largest spot on it is not out at all yet, where normally they are all out full by now. :-(

03/10/2014, 11:56 PM	#3
bskipper Registered Member Join Date: Feb 2004 Location: PA Posts: 64	Ok, on closer inspection with only moonlights on and using a flashlight up close while corals are mostly in, I see it on about 50% of the frogspawn, and it's on the white 'flesh' that comes way down over the hard skeleton. It looks like reddish/brown dots, almost like freckles (lol) and they wipe off very easily. I'm thinking this is not the same black stuff that killed my nepthea a year or two ago. However, I think what is on my sun coral skeleton may be different. It seems hard and crusty, darker brown/black in color and does not scrape off so well. I was able to see some coming off when I tried scraping it, but it doesn't completely come off. Only one of the three is coming out tonight, which is very unusual. I've had this sun coral, which has grown significantly, for almost two years. Any thoughts? I've turned on my UV, which I don't run on a 'normal' basis. I can cut back on the light times more, if that seems to be the culprit. I've replaced bulbs before, but not usually all at once like this time. They were all overdue.