Large sps colony dying from the bottom?

[Animal-Chin]

I have a huge birdsnest colony smack dab in the middle of my tank. Its Gotta be 3 years old and has grown from a tiny frag to the monster it is today. So last week I notice some white at the base but didn't think much of it. Now, entire branches are dying off over night. Its happening fast! I've clipped off the dead stuff to try and prevent spreading but anyone know what could cause this weird shift?

Only factor in my tank that's changed is I've pulled 5 fish to reduce bioload and have water changed my tank aggressively for maybe 2 months to bring my nitrates from 10 down to 5. I was changing 20% weekly.

Could it be a pest attacking?

Parameters

Phos - 0
Nitrate - 5
Cal - 450
Alk 10.2
Temp 80

Everything else in the tank, my acros, monti, lps, zoas, everything is totally fine, its just this one big birdsnest...

[rsisvixen]

From what I've read it seems most corals like some nitrate in the tank.

It could just be yours was adapted to your levels and it changed to rapidly for it to deal with once you removed the fish and did the water change.

Or so I suppose

[Animal-Chin]

Ya I agree and I do still have a reading of 5 so there is some in there. I thought at first maybe the reduction was the issue but I reduced the nitrates over 2 months so it wasn't a sudden shock to the system. I have way more sensitive sps coral in the tank that show no sign of stress either, its just this one big coral.

Gonna dip it tonight I guess. I'm also going to buy another alk test kit just in case mine isn't reading correctly.

[d33ps3a]

If it's huge maybe it's no getting enough light in the bottom? Led lights seem to have that problem. T5 lights have more coverage.

[e46er]

When my birds eat got big it was 20"X20X15 atleast when I fragged him it died underneath as well even tho the rest was happy I just chalked it up to wasn't enough lighting getting to the bottom this was under 2 2x250 mh

[04V10]

What d33ps3a said!

[Animal-Chin]

hmmm maybe. Would this cause the tissue to go from green/pink one day to pure white from the bottom of the coral to the top of some branches in 1 day though? I was cutting off entire dead branches of the coral that were totally healthy the day before. I've never seen anything like it. I'm googling and finding people talking about Rapid Tissue N somethingorother but no one really seems to really understand whats happening. I'm reading alk, I'm reading temp, I'm reading light...lol

So ya, like everything else in reef keeping its a mystery. I'll have to test the heck out of everything tonight.

[whatcaneyedo]

That is my experience with large SPS coral. They reach a maximum size after 3-5 years and then the lower branches no longer receive enough light and flow so they die from the bottom up. At this point I usually haul the entire coral out, break it up, start it over again from a large frag and sell off the rest.

[Animal-Chin]

Thanks for the comments everyone.

[rsisvixen]

Could be that was just it for the lifespan of the coral.

[SeaHorse_Fanatic]

Could be that was just it for the lifespan of the coral.

3 years is a very short time in the lifespan of a coral.

It may also be lack of flow, combined with limited lighting. I know that with a lot of poccilipora sps colonies, the heads on the outside look healthy, but the inside branches are bare or sparse for live polyps.

[Animal-Chin]

I'd believe light over flow but really don't believe either. I have a LOT of both.

Its the colony right under the square back anthias. Its up high so lots of light and in a really good flow area...

http://photogord.webs.com/photos/image.jpg

[rsisvixen]

3 years is a very short time in the lifespan of a coral.


I was reading documentation about cumulative lifespans, they were discussing zoanthids specifically but I don't see why it shouldn't apply to all corals.
The premise is that a coral has a lifespan = to x years and that is built into the genetic code, so in theory you have the original colony, say its got a lifespan of 200 years, its 150 years old when Bob the diver takes a frag/whole colony. This then lives in a tank for x years, fragged, frags live x years, etc, but once those extra 50 years are up, no matter the age of the frags the timer is up and the coral and all its frags die.
The theory being that frags aren't offspring but still part of the original animal and thus subject to the original genetic code.
Was an interesting read.

[Aquattro]

I'd look for pests or something stinging it. Sure, large colonies can start to fade at the bottom, but not in a day or two from a healthy colony. It's location is a premium spot in the tank, lots of flow and light. I do 50% water changes all the time, so I doubt that either, and it wouldn't limit the effect to one colony. something else going on here.

[Animal-Chin]

It is located up and to the right of a huge hammer coral colony, do they every put out sweepers? I've never seen it do it but maybe they do? My galaxy coral sends out sweepers every night, could a hammer? I mean the hammer is 5 years old, I think I would have noticed by now but...

[Aquattro]

It is located up and to the right of a huge hammer coral colony, do they every put out sweepers? I've never seen it do it but maybe they do? My galaxy coral sends out sweepers every night, could a hammer? I mean the hammer is 5 years old, I think I would have noticed by now but...

Yes, hammers can send sweepers quite a distance. That could do it. Also cut off a branch and dip it to see if anything comes off.

[Animal-Chin]

Cut the entire underneath off and gave the rest a good dip. Not one critter fell off so its not pests. Hopefully the stuff I cut off lives, I guess we'll see tonight. Alk is steady at 10.2 so it's not the issue. I moved whats left away from the hammer coral to see if it was being stung.

ah well, I have nice frags of it in my frag tank, I can always start over. Plus open realistate is never really a bad thing when you have a visa card...lol