SPS slowly rotting, doesnt look like STN - PICS

[jimrawr]

Over the last couple days I am noticing that some of my SPS are rotting away. Either at the base or at the tips, but it doesnt look like STN where the tissue is falling off, it looks like even the calcium skeleton is rotting away off the coral. They are deteriorating quick, and hoping someone has experience with this to know what may be the cause. My parameters are pretty darn stable, using bubble magus dosing pump to dose 24 times per day. Here are parameters as recorded for the last 10 days. I am including three tests from 1-20, 1-24, 1-29

Ca: 430, 440, 440
Alk: 9.3, 9.9, 9.9 DKH
MG: 1250, 1300, 1250
PO4: .01, .04, .02
NO3: All three tests look like between .2 and 1.0 on seachem
SG: 1.024
Temp: 77-78
Ph: 8.35-8:45

A couple things that I have changed recently.. I stopped using GFO since when I started to use it I noticed SPS growth stopped completely. Started to use a turf scrubber to help reduce NO3/PO4 instead of GFO. Stopped using Carbon, I hadnt changed it in a few months anyways so just figured not to reuse as I never noticed that it did anything. Since this problem started I put in some fresh carbon. I have ONE lether in the tank which doesnt look to be doing so well, maybe its releasing toxins? Not much else that I can think of that I changed.. Sorry about the blurry pics, tank is a corner tank and its hard as heck to get a nice crisp photo.

These are not growth tips on the birdsnest, they are spots of necrosis..

This is a cyphastrea, and it also has necrosis on the tips which is difficult to see in this picture. They are rotting away..

Could this be the culprit??

 

[tankaddict]

1st thing comes to mind is fish. What kind of fish do you have? Something seems to be nipping on your corals if chuncks of skeleton is "rotting". Keep a close eye on your grazers.

 

[jimrawr]

Hmm I havent added any fish in over a year or so..

1 Yellow Tang
2 Blue Chromis
1 B&W clown
1 Midas Blenny
1 Red Margin Wrasse
1 Anthia

 

[jimrawr]

Maybe its Emerald Crabs? I added 12 about 2 weeks ago to help with some GHA I have.. Going to keep a close eye on them!!

 

[JohnV8r]

Any sudden sudden salinity or temperature swings?

I recently lost a few acropora to a very similar slow tissue deterioration when I added a couple of cabinet fans to my canopy to try to keep the water temp from rising two degrees while my MH's were on. What I wound up doing while I was experimenting with how to keep the temp as steady with the fans as possible was dropping the low temp by another two degrees (total swing of 4 degrees) for a couple nights in a row. That was all it took to set off the deterioration.

Good luck.

 

[reefsurfing]

How quickly did you make all the listed (carbon,gfo, scrubber) changes? The necrosis looks to be consistent to parameter change, a raise in phosphates or both.

 

[toothman]

It looks like they are a bit burnt, from too high kh. I have experienced with phosphate very low like yours, animals will do much better with kh 7 or 8 at the highest. Also mg should be 1300 it is important. Third try some osterfeast at night, or just more feeding.

can you give a full tank shot.

Just let the kh drop it will in a day or two.
Add mg really slow it seems to shock acros if you move mg to quick.
As long as nitrate is less than 10 it is fine.

 

[mroccoralman]

Check acropora eating flat worms probly the culprit dip with coral rx for 4 min and see if flatworms come off the coral. Google what they look like and check for temp swing.

 

[jimrawr]

No swings in temp or alk. I have an Apex and temp doesnt fluctuate more than 1 degree. Salinity stays stable with my tunze osmolator, so no swings there either.

The changes werent made all at once. The GFO was taken offline I think about 3-4 days ago, scrubber added a month ago, and carbon wasnt changed for a few months.

I thought maybe it was high alk also, but 9.9 isnt THAT high, and also its taken with a Hanna which tends to read a bit on the higher side than most test kits as well. Could be this though, I will try to bring it down to 9.

I really think its the emerald crabs now that I think about it, my worst SPS is my birdsnest and I always have one crabs that hosts it at night.. going to try to catch him in action.

Its not flatworm

 

[jimrawr]

Yeah I think it is the emerald crabs.. Looked a bit further into my tank and some LPS also have these marks. Take a look at this favia.. The only thing I have added to the tank lately is Emerald crabs and Hermits..

 

[ebacon]

Prob is the crabs but I'd also be on the lookout for redbugs. It may not be the cause of this issue but it sure won't help

 

[SC Reefaholic]

Crabs! Just put some frags in my new setup and they started losing flesh. I thought I had screwed something up until I saw my emerald crab munching on a birdsnest. He was pulling chunks of flesh off of a healty coral. I thought the green ones were supposed to be reef safe but obviously not in all cases. He is now in the refugium.

 

[jimrawr]

Caught 8 out of the 12, they are going back to the LFS until I can catch the rest. Its not red bugs, Ive had those before and know how to spot them and they also dont take huge chunks out of the SPS like I have. Going to trade these guys is for some turbos

 

[ebacon]

I have a strict no crab policy in my tanks. As a result my snails are huge!

 

[OneReef]

I had a Blenny one time that was biting chunks off my SPS. I caught him biting off flesh and leaving white spots. I removed him and they all healed up nicely.

 

[Cam]

Hi,

Have you thought about low potassium ? I have suffered this in the past and symptoms were similar to yours. If you are running ULNS i.e Zeo, pellets or carbon dosing this can drag the potassium down too low.

Cam.

 

[reefsurfing]

Nice, glad to see you found the problem, now to just get them out.

 

[jimrawr]

down to three left

 

[stevedola]

I dont know...Id say maybe the crabs but more likely the culprit is discontinuing GFO. Im not saying to restart using it but that could be why they all took a turn downhill. A better course of action would have been to taper the GFO like you would if you were to quit smoking. A sudden shock going cold turkey can stress out sensitive corals. I would bet that the corals will rebound as they adjust to the new water chemistry but monitor closely so you dont lose anymore tissue.

 

[stevedola]

One thing to note is that even though we (as hobbiest) quantify the relationship between nutrient export filtration by a number achieved on a test kit...our corals most likely dont react the same way that the test kit registers. I mean, just because the test kit reads 0 phosphates with GFO and then reads 0 phosphates while using an algea scrubber, it doesnt mean that the corals obtain the same nutrition (so to speak). IME there is a difference and that is why in my opinion it is always better to make small incremental changes than large drastic changes (Esp. to SPS corals) when utilizing new chemicals/media/filtration methods.