Some SPS corals keep completely stripping rapidly from the base up and I don’t know why.

[Fisherman Joe]

I have run a Triton test and all parameters are within normal parameters, nothing obviously wrong. My tank is 600L and 2 years old and I’ve been doing this hobby for more than a decade now so I know the basics lol.

The last few months I have had the occasional coral completely strip from the base up within 48 hours.

My temp swings from 25.5C to 26.0C at the most. My alkalinity is controlled by the KH Director from GHL And swings from 8.5 to 8.0 occasionally. Sometimes my pH is 8.4 however but not often. Usually around 8.3.

Sometimes my skimmer will over skim and then the top off will add too much fresh water. Occasionally the Salt gravity will drop from 1.026 to 1.025 or maybe 1.024 over 24 hours.

These are the only things I think could cause it.

My NO4 is 5-10ppm. My PO4 is 0.1 on average and swings up to 0.15 and down to 0.05 at times.

calcium is 430 and mag is 1440.

What’s the most likely cause here?

 

[Ashibashi]

Do you have a picture of what it looks like? What are you using to test?

 

[Ashibashi]

Sorry just saw you said triton.

I'm new to this so not much use I'm afraid. Following to see what gets found out, though.

 

[Fisherman Joe]

The coral will just undergo rapid tissue necrosis and all the flesh peels off the skeleton leaving the white coral skeleton underneath.

 

[Randy Holmes-Farley]

Maybe it's a biological issue, such as a pathogenic bacteria.

Maybe a fish is causing it?

Can you post the ICP results? Which ICP company?

 

[Fisherman Joe]

UNWANTED HEAVY METALS ANALYSIS SETPOINT
Hg MERCURY 0 µg/l 0 µg/l
▲
Se SELENIUM 0 µg/l 0 µg/l
▲
Cd CADMIUM 0 µg/l 0 µg/l
▲
Sn TIN 0 µg/l 0 µg/l
▲
Sb ANTIMONY 0 µg/l 0 µg/l
▲
As ARSENIC 0 µg/l 0 µg/l
▲
Al ALUMINIUM 0.023 µg/l 0 - 60 µg/l
▲
Pb LEAD 0 µg/l 0 µg/l
▲
Ti TITANIUM 0 µg/l 0 µg/l
▲
Cu COPPER 0 µg/l 0 µg/l
▲
La LANTHANUM 10 µg/l 0 µg/l
▲
Sc SCANDIUM 0 µg/l 0 µg/l
▲
W TUNGSTEN 0 µg/l 0 µg/l
▲
MACRO-ELEMENTS ANALYSIS SETPOINT
Na SODIUM 11124 mg/l 10000 - 11300 mg/l
▲
Ca CALCIUM 426 mg/l 415 - 520 mg/l
▲
Mg MAGNESIUM 1443 mg/l 1320 - 1500 mg/l
▲
K POTASSIUM 427 mg/l 380 - 480 mg/l
▲
Br BROMIDE 69 mg/l 62 mg/l
▲
B BORON 4.295 mg/l 4.5 mg/l
▲
Sr STRONTIUM 6.685 mg/l 8 - 12 mg/l
▲
S SULPHUR 952 mg/l 900 mg/l
▲
LI-GROUP ANALYSIS SETPOINT
Li LITHIUM 210 µg/l 200 µg/l
▲
Ni NICKEL 1.65 µg/l 5 µg/l
▲
Mo MOLYBDENUM 14 µg/l 12 µg/l
▲
I-GROUP ANALYSIS SETPOINT
V VANADIUM 7.988 µg/l 0 - 3 µg/l
▲
Zn ZINC 1.061 µg/l 0 - 5 µg/l
▲
Mn MANGANESE 1.77 µg/l 0 - 3 µg/l
▲
I IODINE 39 µg/l 30 - 90 µg/l
▲
FE-GROUP ANALYSIS SETPOINT
Cr CHROMIUM 0 µg/l 0 µg/l
▲
Co COBALT 0 µg/l 0 µg/l
▲
Fe IRON 0 µg/l 0 µg/l
▲
BA-GROUP ANALYSIS SETPOINT
Ba BARIUM 18 µg/l 0 - 10 µg/l
▲
Be BERYLLIUM 0 µg/l 0 µg/l
▲
SI-GROUP ANALYSIS SETPOINT
Si SILICON 159 µg/l 0 - 200 µg/l
▲
NUTRIENT-GROUP ANALYSIS SETPOINT
P PHOSPHORUS 45 µg/l 6 - 23 µg/l
▲
PO4 PHOSPHATE 0.1377 mg/l 0.018 - 0.07 mg/l
▲

 

[duke62]

Are these maricultured SPS, wild pieces or are they aquaculture pieces?

 

[Fisherman Joe]

Are these maricultured SPS, wild pieces or are they aquaculture pieces?

Maricultured

 

[duke62]

There’s your answer right there.

 

[Fisherman Joe]

There’s your answer right there.

Care to expand on that?

 

[Dkeller_nc]

I'm guessing Duke62 is referring to the issue that's common with maricultured corals, which is lots of critters that come with them that like to eat coral. There's tons of these - acropora-eating flatworms and so-called "redbugs" being a couple of notable examples.

 

[REEFTIDE]

Care to expand on that?

Maricultured SPS are a lot more challenging to keep for the most part. Not only are they prone to have lots of pests(Black bugs, white bugs, red bugs, flatwormd etc) but they also have to transition from life in the ocean to living in a box filled with water.
We don't recommend them for beginners and honestly, its still difficult for experienced reef keepers as well

 

[DivingTheWorld]

Those Salinity and Phosphate swings seem a bit extreme. I’d recommend making changes to keep those more steady. Acros don’t like big changes.

 

[Huskymaniac]

Probably a bacteria RTN. Tank may be toast, sorry.

 

[duke62]

Care to expand on that?

Maricultured Acropora are known to RTN without hesitation. While they are cheap and very hard pass up the opportunity to purchase because of how cheap they are, there are reason why. Not only do they come with every pest known to the industry and if you do not have a dedicated QT for them risk your whole system. So when you see aquacultured Acropora 1” frags going for 3 to 6xs the price of maricultured pieces that have had 3 or more generation to be acclimated to our small water boxes, you now know why they are priced they way they are

 

[Fisherman Joe]

Another one has done it today. No known cause.

 

[Fisherman Joe]

Polyps open on top, feeding, happy.

Dying on the bottom

 

[Huskymaniac]

Polyps open on top, feeding, happy.

Dying on the bottom

Would clip a peice of healthy tips and chuck the rest.

 

[Micro-Reefs Aquarium]

I have 21 SPS frags that I purchased from my LFS colony tank. I have 6 months in with my system dedicated only to SPS, keeping all variables within the numbers to keep them steady to grow, I have had one frag enter RTN and I under the guidance of my LFS, salvaged what I could and used Dr. Tim's Eco-Balance.

It helped, and the RTN piece that was salvaged lived 1 more week before it started to RTN again and I removed it as a loss in my tank.

The other 20 frags, continued to do well with about 3 of them hitting STN all from the bottom up. I quickly salvaged them and used Eco-Balance and they are still alive today, that is about 30 days ago. If they are going to continue to RTN or STN, it will show up within 24 hours and kill the remaining colony.

Some frags do better than others, that I have seen, digitata and tenius for me were just solid. Conversing with my LFS, even in his 300 plus system that is all SPS only, he has occassionally STN, and RTN hit, it's almost like some colonies fade quickly due to changes that cannot balance to, my opinion.

I just wanted to share my experience with my SPS small 12 gallon I have been running since January this year, since I saw your title about RTN/STN from bottom up, I experienced that and had to glue/frag remaining unaffected area with the Eco-Balance trying to reboot good bacteria into my tank, I don't know what worked but I followed what the LFS told me to try.