Some SPS not doing well

[kratosxxl]

Hey folks, I’m having a hard time figuring out what’s going on with my tank. It all started with the birdsnest corals—two of them started bleaching and losing tissue from the bottom up. Now I’ve noticed that my blue Acro is starting to bleach in the middle as well.

Here are my current parameters. I’m planning to run an ATI ICP test to see if it can help identify any potential issues.

Has anyone experienced something similar or have any ideas about what might be causing this?
Im dosing 720 ml kalk (avast stirrer) overnight in 12 doses. WCH 20 % every 2 weeks (tank is IM EXT 200)
Filtration is 2x N-Clear M roller
Deltec 1500i skimmer
Wave 2x Maxsepect xf350

Ill add some coral pics in a bit

 

[kratosxxl]

Here are some pics with troubled corals

 

[kratosxxl]

No blue light pics

 

[painter1982]

Hard to say. But stability is key. I’m not sure what your history of parameters are. I’d get an icp ms test and test the same sample with your method to see if you are accurate.

 

[kratosxxl]

Hard to say. But stability is key. I’m not sure what your history of parameters are. I’d get an icp ms test and test the same sample with your method to see if you are accurate.

But why bleaching in the middle ? Is it common with sps ? I did had some fluctuations with alk and ph.
So not sure if related but i 3d printed some frag mount with petg (reef) safe and both were glued to it so just to be safe i removed everything 3d printed.

 

[painter1982]

Hard to say. But stability is key. I’m not sure what your history of parameters are. I’d get an icp ms test and test the same sample with your method to see if you are accurate.

But why bleaching in the middle ? Is it common with sps ? I did had some fluctuations with alk and ph.
So not sure if related but i 3d printed some frag mount with petg (reef) safe and both were glued to it so just to be safe i removed everything 3d printed.

Alk and salinity fluctuations can cause the rtn you are seeing. It’s not bleaching. That’s different looking. Bleaching is the coral expelling the zooxanthellae and turning pail. It looks like you are experiencing rapid tissue narcosis (rtn). I’m no expert on this. I’ve seen it when I had fluctuating parameters. I don’t see it anymore since I achieved stability