Bleaching SPS

[pwendlandt]

Hello everyone,


I just got back from a 7-day trip and found two of my SPS corals (one new frag, one older one) are bleaching and looking very stressed. I'm trying to make sure I'm doing everything I can to save them and would appreciate any advice.


Here are my full parameters, tested just now:


• KH: 8.3 dKH


• Calcium: 460 ppm


• Magnesium: 1350 ppm


• Salinity: 37 ppt (Specific Gravity ~1.028)


• Phosphate: 0.18 ppm


• Nitrate: 20.2 ppm


• Temperature: 25 C

My corals:
My Coral List:


• SPS (Bleaching):


• 1 of my 2 older SPS frags


• 1 of my 2 brand new SPS frags


• SPS (Not Bleaching):


• The other 2 SPS frags


• other corals (Seem OK):

• Goniopora (small)

• Red Goniopora

• Cyphastrea

• Lobed Brain Coral

• Hammer Coral

• 1 LPS frag

• Purple GSP

• Zoas (looking even better than before the trip)

• Pulsing Xenia

• Toadstool (for some reason changed position and is now more inclined to one side)

• Photosynthetic Gorgonia

• 'Hulk' frag


Important Context:


1. The Salinity Spike: The 37 ppt salinity is high because my ATO reservoir ran dry while I was away. I have just refilled it with fresh RO/DI water, so it is now slowly bringing the level back down to 35 ppt. This seems like the most obvious cause of the bleaching.


2. Nutrient Levels: I know my Nitrates (20.2) and Phosphates (0.18) are still very high, and I've been battling algae. The good news is these numbers are actually down significantly from last week (they were 23.6 and 0.50 before my trip).


3. My System & Dosing:


• Tank: 20-gallon (75L) All-In-One.


• Filtration: Bubble Magus MiniQ skimmer and filter floss (which was changed by someone twice during the 7 day trip.)


• Dosing (Automated): I am running a 4-pump doser.


• KH (Part A): My automated doser ran perfectly and kept my KH stable at 8.3 the whole time I was gone.


• Ca/Mg (B & C): These pumps are OFF, as my levels are stable/high.


• Phosphate Remover: I am auto-dosing 3.5ml/day of diluted Elimi-Phos, which is what helped my PO4 drop from 0.50 to 0.18 while I was away.



The corals are glued in place, so I can't move them to the sandbed.

My main theory is that the high-salinity shock (37 ppt) was the trigger maybe?

Is there anything else I'm missing that could be causing the bleaching?


2. My plan is to let the ATO fix the salinity slowly, reduce my lighting, and keep up with my automated dosing and every 2-3 days change filter floss.

Thanks in advance for any help!


The last two imagines are from how it looked like before

These are from before the bleaching

 

[Lavey29]

Numbers are fine with bringing salinity down slowly. Nutrients are fine and did not cause this. How old is the tank? How long have the frags been in there? What par are they in? Pictures appear dark.

 

[pwendlandt]

I do not know the par but I know they are at the very top of the tank. The tank is almost two years old now. Here’s a picture of where they are placed there are other sps corales there that seem fine if fact a brown coral I was given is now looking greate which I find even stranger

The light is a AI prime

 

[Lavey29]

I do not know the par but I know they are at the very top of the tank. The tank is almost two years old now. Here’s a picture of where they are placed there are other sps corales there that seem fine if fact a brown coral I was given is now looking greate which I find even stranger

The light is a AI prime

Its possible the salinity change affected them because that probably raised alk too. Have you done a recent ICP test to check everything?

 

[pwendlandt]

Its possible the salinity change affected them because that probably raised alk too. Have you done a recent ICP test to check everything?

No I have not done ICP test, I checked all my parameters before fixing the ATO tho. Also to answer previos question, the green drag has been there for a few months and the blueish frag no longer than 3 and a halve weeks