Maze Brain receding

[Salt1972]

Our maze brain frag was just beginning to spread after 6 months... until earlier this week when it began to recede. Pic below.

Parameters:
Salinity - 1.026
Temp - 79.9
Alk - 8.5
Calc - 497
Mag - 1440
NO3 - 3
PO4 - .021

Parameters have been very stable.

 

[malacoda]

Have you changed your lighting or flow? How about your dosing (if you're dosing), any changes to schedule or type/brand of dosing components, the salt you use, or anything like that?

 

[Salt1972]

Have you changed your lighting or flow? How about your dosing (if you're dosing), any changes to schedule or type/brand of dosing components, the salt you use, or anything like that?

Lighting has not changed - we have 4 Kessil 360's on a spectral controller. No change in position, schedule, or intensity. We does BRS 2 Part and we've made no changes. Salt is Reef Crystals - no change. All parameters are measured each week... we've been stable sans a slight decrease in PO4 from .06 to .02 that may have accompanied feeding less since our livestock was depleted.

The only exception was our disaster with bleach, but that was in April and the maze has since been growing. All other corals - SPS, LPS, Soft, etc. are thriving.

 

[malacoda]

Hmm, afraid I'm kind of at a loss then.

It didn't look like it from your pic, but are there any other corals near by that my be sending out sweeper tentacles and attacking it at night?

The only area I see that looks like it might be recession is in the shaded area along the left of the frag plug. And the only time I've ever seen recession of that nature is when there was a change in flow. Hopefully someone else will chime in with some other potential insights...

 

[Salt1972]

I'm not sure what's happening... our maze brain has continued to waste away and our Sunset Monti (which has been thriving) just melted away over a 10 day period.
Before:

After:

Before:

After:

Parameters are stable:
Salinity - 1.026
Temp - 79.9
Alk - 8.6
Calc - 486
Mag - 1430
NO3 - 2
PO4 - .029

We use a combination of chaeto and caleurpa in a refugium to control nutrients. Both of those algaes are also receding. I'm wondering if this is related to the reduction in bio-load that came with our catastrophe in April? We have a pair of mocha clowns and a compliment of CUC, but no other bio-load. Could a reduction in nutrients cause the maze brain and monti to die? We have some jingle bells cyphastrea, GSP, Duncans, Frogspawn, and palys doing well.