acans dying - what that coming out?

dipped the rock, lots of die off.. I think the string kindda thing on the right fell off too since it was a coming out of a hole that was open from the other side/bottom of the rock.

its in a shaded area but photoperiod is 8hrs - starting from a gradual low intensity all the way to 100% for 2hrs and then gradually back down --- is that good for all corals? or should I have it at 8hrs of high intensity?

Corals - Birdsnest, Acans, Plate Coral, Goniapora, Mushrooms and a few zoa frags.

 

What kind of lighting?

 

Local brand but I'm sure I've seen the same being sold with a big brand name online.
Probably made in china.

its 88×3w LEDs with a dimmable timer.
white 18000k 16pcs,
white 14000k 16pcs
white 10000k 16pcs
bule 460nm 26pcs,
moon light bule 453nm 14pcs

actinics on 9am
whites slowly start up at 11am
brightest at 2pm to 4pm
then gradually go lower to switch off at 7pm
moon lights remain on for another 2hrs
all out at 9pm

I've yet to do a PAR test

 

To be honest, the original blue and white led's simply did not make the cut when it came to growing corals. There are some good thread write ups here if you'll be willing to commit some of your day worth of reading. The newer lights come with a variety of spectrums that provide a much healthier environment, and even those need fine tuning.

 

Not exactly...

Blue/White did/has worked fine for many, and can grow corals quite well. I did for me and I've seen it work for others as well. However, what the blue/white did lack was some coral coloration for many. That's where the full spectrum part comes in.

As for the OP's problem, I doubt it's a lighting issue. The pictures to me show a very stressed and dissolving acan, which could be a variety of things, ranging from water parameters to a bacterial infection. It's going to be difficult to put a finger on what exactly happened to them.

 

did you ever say if you were target feeding them or not???? If so i apologize that i missed it.

It appears that either as mentioned above something is irritating them, or i believe they are starving. My acans would readily accept meaty foods every couple days. I fed mysis and then moved onto krill. Each polyps will share its foods with other polyps so you do not need to feed every polyp but you do need to feed a lot of them

 

Gall grab. I can see him in there. Cryptochiridae. They are not harmful themselves, but they can irritate. Not enough to kill the whole colony, just the areas directly around him.