Need some help - Encrusting coral croaking

[Drew in Texas]

I have this years old healthy encrusted coral that has just gone south. Went from fine (rust colored with orange spots) to what you see (mostly gray) in about a month. The only thing different was a dose of Reef Roids. Everything is healthy and thriving. Water parameters are perpetually 'perfect' (they've been super stable and almost exactly the same for at least 5 years). 150 gallon, red sea premium salt, 35g water change every 2 weeks for the last decade, clean up crew are good, fish are all good, large variety of other corals, including other encrusting, are fine.

Any of you reef/encrusting coral gurus have a clue what its problem might be? I'm about ready to call Scooby Doo, because it's a big mystery.

#reefsquad

 

[mta_morrow]

Looks like a chalice. Have there been any changes with your lighting?

A big blast of reef foods may have spiked nutrients as well.

Any new fish or inverts?

 

[ZoWhat]

Classic sign of Alkalinity being too high.

Get your Alk tested in dKH. Anything over 12/13dKH is borderline burn out of that Miami Hurricane chalice

 

[Drew in Texas]

Looks like a chalice. Have there been any changes with your lighting?

A big blast of reef foods may have spiked nutrients as well.

Any new fish or inverts?

'Morrow...

2 foxface for fish, no new inverts. No changes in lighting, but I'll move it to someplace a little less bright.

Plan B:

My ph is as it has always been. As I said, my tank parameters are rock solid, stable for years. I've got a Hanna alk checker coming via Prime, so I'll know pretty quick. I added the reef roids, and don't often 'blast' anything. I am generally very careful, adding nutrients and anything else gradually. Easy to add more, catastrophic at times adding to much. Can't help it, just how I am...

*New Info* My lovely bride has been dosing alk and mag at the suggestion of the LFS guy. She'll be stopping that now until we are able to see what the levels are.

I'm guessing everyone is partially right... too much light and the alk is probably a little high. I'll update as I get info from home (I'm on assignment in Alaska, tank is in Texas). Carol loves the tank as much as I do, and we both want that chalice to make it. Thanks to both of you for your advice.

 

[mta_morrow]

'Morrow...

2 foxface for fish, no new inverts. No changes in lighting, but I'll move it to someplace a little less bright.

Plan B:

My ph is as it has always been. As I said, my tank parameters are rock solid, stable for years. I've got a Hanna alk checker coming via Prime, so I'll know pretty quick. As a point of reference, as a chemical engineer I don't often 'blast' anything. I am generally very careful, adding nutrients and anything else gradually. Can't help it, just how I am...

*New Info* My lovely bride has been dosing alk and mag at the suggestion of the LFS guy. She'll be stopping that now until we are able to see what the levels are.

Definitely check alk! May very well be an alk burn.

Also, a foxface may have taken a nibble. Watch to see if the spot grows as well as keep an eye on the foxface

 

[GThompson]

The Hanna alk tester is really easy to use so if it shows up at your house before you can, your wife will have no problem using it to test with. And be glad your wife enjoys it. Mine calls me an idiot for spending anything on mine. Lol

 

[ZoWhat]

You say your numbers are rock solid.... yet you don't post when you're doing tests, who's the Mfgr of the tests you're using, if the tests are nearing an Exp date......and what the exact test result numbers are.

It will continue to be a mystery if you keep vital info a mystery to us......

 

[Drew in Texas]

The Hanna alk tester is really easy to use so if it shows up at your house before you can, your wife will have no problem using it to test with. And be glad your wife enjoys it. Mine calls me an idiot for spending anything on mine. Lol

************************************************

My wife was even OK with getting the black tang, which is acclimating to the DT (after a month in coppered QT) as I write this! Go figure... I may well have a unicorn!

Skim;

I understand you don't know me or my experience, so I accept your premise. I've had a coral tank or two for many years, decades in fact. Had one fish die off due to velvet (wasn't QT my new fish at the time - lesson learned) and, knock on wood, never had a coral die off. Because I don't have anything overly exotic, I shoot for the 'commonly accepted' marine tank parameters. I have a VERY stable tank, and everything except that one chalice is absolutely thriving - a variety of corals, fish, even my hollywood stunner chalice is SUPER happy and growing like a weed... My parameters rarely if ever even wobble. I need to give my clean up crew a bonus!

All tests are API except we use a refractometer for salinity and an electronic ph meter that we keep calibrated. Testing is done twice a week on 3 tanks, so the chemicals stay fairly fresh.

Readings from this morning (8/20) from our main DT (where the chalice is):
Na: 1.020
pH: 7.92 - Seems a little low to me, but my tank stabilized there years ago and everything seems to be thriving.
Nitrates: 0
Nitrites: 0
Phos: .25
Ammonia: .25 - Normally zero - but stirred up the sand yesterday moving the rocks around to get the chalice into a little darker area. I suspect they'll be back to zero next time she tests.

Hope that satiates your curiosity.

Again, thanks for the input.

 

[Drew in Texas]

*Update 8/21* ALK is only 8.6 per our brand new Hanna ALK tester. This has to be a lighting issue based on advice here and what I've read. Moved it a couple of days ago to the bottom and a darker area of the tank. Fingers crossed...

Here's a pic of my Hollywood Stunner chalice, alonf with my new black tang and my marine betta who never hides...