Green acro murder mystery

[VoiceInTheDeser]

I've acquired a few sps frags in the last few months. One, a green acro, was doing just fine until two days ago. I woke up to 75% of the flesh stripped to the skeleton. I had added a "reef safe" strawberry crab about a month ago. I immediately suspected him. He's nocturnal, so i turned off all the lights and waited for him to emerge.

Caught him, dropped him in fuge. Next morning, rest of coal is stripped clean.

So since i know he was in the fuge, what killed the rest? I do have some hermits, but just snails, two occ clowns and a melenarus wrasse other than that. Would any of those take the opportunity on a damaged coral or do you think the real killer is still at large? Other than the strawberry crab, I haven't added any livestock since the frags were added.

 

[71xlch]

Rapid Tissue Necrosis (RTN) Doubtful a critter did it.

I've acquired a few sps frags in the last few months. One, a green acro, was doing just fine until two days ago. I woke up to 75% of the flesh stripped to the skeleton. I had added a "reef safe" strawberry crab about a month ago. I immediately suspected him. He's nocturnal, so i turned off all the lights and waited for him to emerge.

Caught him, dropped him in fuge. Next morning, rest of coal is stripped clean.

So since i know he was in the fuge, what killed the rest? I do have some hermits, but just snails, two occ clowns and a melenarus wrasse other than that. Would any of those take the opportunity on a damaged coral or do you think the real killer is still at large? Other than the strawberry crab, I haven't added any livestock since the frags were added.

 

[Pife]

It was a change in your tank that caused it. . Not the crab.

 

[moatdaddy]

What are your parameters?

 

[outssider]

once rtn starts, it proceeds very quickly and can't be stopped. In this case your only alternative is to frag a piece of the healthy part quickly, this is the only way to save some of the original colony. rtn usually occurs with unstable parameters but can occur for no apparent reason at all.

 

[VoiceInTheDeser]

Huh, so my water changes have slowed down a bit since my baby arrived. I just did tests and came out with

Ca: 500
NO3: 10 (shame )
Alk: 7
Salinity: 1.026

The one that could have dropped "suddenly" actually would have been salinity. I added 2.5 gallons of RO water last night as a top off. That means before that, the salinity in my tank would have been around 1.028 before that. Some of the others are iffy, but wouldn't have changed "quickly." The salinity would have done so relatively quickly, by comparison. I normally have it around 1.024 so that evap doesn't let it get above 1.026.

The frag is completely dead now, so I guess it's a moot point, but I do have a few other SPS frags that I'm hoping to keep healthy. Guess I'll do a few water changes to bring NO3 down and bump Alk up, but I don't think anything in those results is egregious.

It was sitting on a frag rock next to a Pavona and Pocillopora. Don't think either of them would have suddenly started stinging it to death.

Also, I guess I'll let the crab out of jail. He seemed to be helping the display by cleaning up, I just immediately suspected him of foul play.

 

[moatdaddy]

I don't think a 10 nitrate would kill them. I have had SPs in some garbage water after a surgery. Mind you it got that way slowly. That's what I find SP's hate. A rapid change in almost any parameter. Honestly I say you buy one more and watch parameters more closely to see if its coral warfare or a critter. I say that for your sanity too. You must not be overconsumed by the baby. Most of us have been there. Congrats and start planning a kid free vacation. Preferably somewhere you can bring home coral.

Buy a second frag rack. I never put sps by anything other than zoanthids. I know you can but I play that on safe.