What do you think caused this tissue recession?

[Creggers]

Hello R2R,

Wondering if you all could possibly take a look at this Platygyra and tell me what could possibly be causing this tissue recession. I have it in low / moderate flow and around 200 (an assumption). I don't have any fish in the tank that are known coral nippers, the only questionable fella would be the lawnmower blenny but I sincerely doubt he'd be taking bites of this.

I will say that for some reason I've had trouble keeping corals like this in the past, but my tank has now been up and running for 10 months, and I should be able to stock lightly without running into any issues.

Levels over the past 30 days:
ALK: 8.1-8.4
CA: 500-540 (I know this is high but I'm letting it come down)
MAG: 1250 - 1300
PH: 8.0-8.3
TEMP: 77-79
NO3: 5-10 (hard for me to tell on test kit where it falls)
PO4: .1-.2


30 days ago:


Today:

 

[vetteguy53081]

I’m many cases it’s high:
Light
Flow
Alk
Ca
Nitrate

check All of the above

 

[Creggers]

I’m many cases it’s high:
Light
Flow
Alk
Ca
Nitrate

check All of the above

So I know that my Calcium is a bit high as my trident has it reading out around 510 or so. I've been letting it come down naturally over time. Is it really likely that that's the culprit? Not sure there's anyway to really lower that outside of just waiting it out.

 

[vetteguy53081]

So I know that my Calcium is a bit high as my trident has it reading out around 510 or so. I've been letting it come down naturally over time. Is it really likely that that's the culprit? Not sure there's anyway to really lower that outside of just waiting it out.

If not the culprit , a contributor

 

[Wasabiroot]

I wouldn't count out the lawnmower quite yet. They have been known to nip at LPS. I had a bicolor that stripped a Platygyra to the skeleton when I wasn't looking.
Also, don't forget salinity!

 

[Creggers]

I wouldn't count out the lawnmower quite yet. They have been known to nip at LPS. I had a bicolor that stripped a Platygyra to the skeleton when I wasn't looking.
Also, don't forget salinity!

Ah yes - my SG is at 1.026. I always leave that one out.

Maybe the lawnmower is somewhat at fault, I haven't seen him bothering it and I keep the tank well fed so I'd be surprised but who knows. I'll try to keep a closer eye on him and see if he's the culprit.