Scoly is receding for some reason!

[JustinMN18]

Hello,

My scoly that I've had for several months is starting to recede for no apparent reason.

I went home last weekend, Friday morning - Sunday morning, and when I came home, it was like this.

The coral isn't next to anything that can sting it I think. It is next to a tachyphylia or however it's spelled. Parameters are

Salinity 35
Phosphate 0.1
Nitrate 15-20
Alk 10
Calcium 440
Magnesium 1350
Temp 77.5
Light is roughly 120 par

 

[JustinMN18]

Nothing?

 

[Shirak]

How often do you feed it?

 

[monkeyCmonkeyDo]

Its in low to med flow?
D

 

[JustinMN18]

How often do you feed it?

Every other day some frozen mysis or benefeed.

 

[JustinMN18]

Its in low to med flow?
D

I think so haha

 

[Shirak]

So light and feeding are good then. I would look at flow as suggested by monkeyCmonkeyDo. I would suggest some rubble around them to stop the flow from hitting them directly on the sides. Or try moving them closer to the rocks so they are not hit by flow from the sides

Look into your parameter swings also. Parameters look ok although I don't run my alk over 9 and your NO3 and PO4 are getting on the high side. So maybe up the water changes a bit.
More importantly how do your parameters move through the day and longer term over a weeks time.