Spontaneous RTN in one part of the tank?

[deputydog95]

Second time this has happened.

First time was about 3-months ago. I had around 5 small colonies RTN over the course of a couple days. All within a foot of each other. As quick as it started, it stopped. A couple that started to go but just stopped RTN'ing in the middle of all this, and are finally bouncing back.

Now it's happening again. I had two small SPS colonies disappear almost overnight and it's bearing down on a 3rd one. All within about 6 inches of each other.

Same part of the tank as the first time. Lighting is the same across the entire tank. The only that that is different on that side is that's where I have my Gyre, but this stuff has been sitting there happy in the same spot for a long time so I can't believe it's a flow issue. No signs of bugs or pests... And I assume if that were the issue, they would have been munching stuff the whole time versus this start and stop stuff. Parameters are fairly stable, no real issues there.

It's the top right of my tank. No issues that I'm aware of anywhere else.

Any suggestions? Clearly, I'm missing something...

 

[rvareef]

post some pics of the corals and full tank shot

 

[Tripod1404]

What is the lighting? When I used MH bulbs something similar once happened to me. It turned out I had a bad ballast that some how was causing the corals below the bulb that it is powering to RTN (maybe excessive UV due to uneven power, I dont know).

Also keep in mind stressed corals under high flow can rtn pretty rapidly because a small tissue recession can get bigger as the flow peals off more skin. What are your watere parameters.

 

[jda]

Check again for pests. They can reach a critical mass where local stuff dies, then they die back since they lose the hosts and need time to regroup, move and start over again.

 

[deputydog95]

I'm using 3 Kessil 360's.

 

[deputydog95]

IMG_20180405_193738 by https://www.flickr.com/photos/deputydog95/, on Flickr

 

[deputydog95]

IMG_20180405_193727 by https://www.flickr.com/photos/deputydog95/, on Flickr


IMG_20180515_131542 by https://www.flickr.com/photos/deputydog95/, on Flickr

IMG_20180515_131538 by https://www.flickr.com/photos/deputydog95/, on Flickr

IMG_20180515_131533 by https://www.flickr.com/photos/deputydog95/, on Flickr

[/url]IMG_20180405_193727 - Copy by https://www.flickr.com/photos/deputydog95/, on Flickr[/IMG]

IMG_20180405_193758 - Copy by https://www.flickr.com/photos/deputydog95/, on Flickr

 

[Relativity]

Usually its from using GFO are your phosphate levels going up and down has anything died like turbo snails in the tank

 

[ramseynb]

Is alk stable?

 

[rvareef]

very nice tank, I would clean and disassemble your vortechs and check for rust

 

[tmc1313]

It's hard for me to tell from my work PC (not the best resolution), but are all the corals you're having issues with monti's? It looks like it, from what I can make out. If so, I would highly suspect monti eating nudi's chomping away at them.