Corals bleaching after feeding?!

[Emhriverdale]

Howdy!

 

I've been broadcast feeding with Reef Roids a few times a week. Yesterday I did my first target feeding yesterday. Several SPS/LPS started bleaching (I think) within hours. Palys and Zoas look happy. I have a monti that has been lovely and slowly growing for months, turning white as we speak. Did a 15% WC 48 hours prior to feeding, getting ready to do another now. I tried turkey basting, no change.

 

Only other system issue was a heater which I forgot to plug in after WC overnight - but temp only dropped to 78. My unkillable gramma who, a month ago recovered from a bad injury on his cheek, had popeye on the same side - I'm assuming latent infection as I didn't treat. It's well recovered now and he's eating like a pro. 

 

Parameters just prior to the feeding - 1.025/80F - pH8.0/Nitrate 5/Phos .1/Ca 500/Alk 10/Mg 1280/Ammonia 0 - not yet chasing trying to dose, cause I listen to my WAMAS friends. Test values unchanged just now after bleaching started. I have 2 black box LEDs and 1 XR15. Coral in the picture has been in the same place for months. Only change was the target feeding.

 

Could the feeding have stressed? Could this be a growth spurt from being fed for the first time?

 

Thanks for the assistance!

 

Edit: 55g DT - 28g sump w/ fuge, no skimmer. 

 

 

 

 

Edited August 8, 2021 by Emhriverdale

[DFR]

I wouldn’t suspect the feeding as the cause unless there was a noticeable nutrient spike (which doesn’t seem to be the case).  
The lighting seems kind of excessive for a standard 55g.  Do you run them all at 100%?  If you haven’t already, I’d perform a PAR mapping on the tank.

As it is only the stony corals, it could also be temp related.  I’ve lost sticks that we’re doing well for a long time, following a sizable water change that was not the same temp as my tank.

[Emhriverdale]

Thanks for the fantastic guidance fellow Riverdalian! 

 

Upon further research, directly plopping a paste of Reef Roids on them is NOT the ideal method for target feeding.  My nutrients spiked subsequently, but things are settling down - and I have most definitely learned my lesson!