Help with Short Tentacle Plate

[dtesenair]

A couple of weeks ago, I noticed that my plate coral had a small section at the edge that seemed "pinched" in. Well, that section has slowly and steadily opened up and receded from the skeleton. Any ideas what is going on? Here are a few of my water specs...

pH - 8.1 (Currently adding buffer to bring it up)
SG - 1.023
Nitrate - <20
Nitrite - 0

I've attached a picture. Any help would be appreciated.

 

[brannock_16]

Sg is a bit low...natural sea water is 1.026

What is your calcium, alkalinity, and magnesium?

 

[dtesenair]

Sg is a bit low...natural sea water is 1.026

What is your calcium, alkalinity, and magnesium?

Thanks for the quick reply, brannock! I tested my Calcium and it is at 360, a little low. I don't, however, have a way to test alkalinity or magnesium so I'll have to take a sample to my LFS or get a test kit tomorrow.

I checked the pH again and it read 8.2 this time.

As for the salinity, I know it's on the low end but liveaquaria.com (and others) suggest keeping the SG between 1.023 and 1.025 but it seems that most folks on the forums suggest slightly higher. Why the disconnect?

And, most importantly, are you thinking that any of the water parameters might be suspect in my poor coral's condition? :-(

 

[brannock_16]

Thanks for the quick reply, brannock! I tested my Calcium and it is at 360, a little low. I don't, however, have a way to test alkalinity or magnesium so I'll have to take a sample to my LFS or get a test kit tomorrow. Yes your calcium is quite a bit low. I try to shoot for anywhere between 420 and 480 ppm on my LPS dominant tank. You really need to pick up an alkalinity test...alkalinity plays a HUGE role in the calcification of corals and Alk and Ca need to be constant and within acceptable ranges for corals to not only live, but thrive.

I checked the pH again and it read 8.2 this time. Ph fluctuates on a daily basis. If you test your Ph during the time that your lights are out it will be much lower than when your lights are on. One way to stablize the Ph is to run a reverse photo cycle on your refugium (given that you have one).

As for the salinity, I know it's on the low end but liveaquaria.com (and others) suggest keeping the SG between 1.023 and 1.025 but it seems that most folks on the forums suggest slightly higher. Why the disconnect? I think that liveaquaria.com and others suggest the 1.023 to 1.025 as a general guidelines for fish and some soft corals. But actual testing of natural sea water shows a SG of 1.026. This is the SG that I have the most success and all my corals appear healthiest and display best color and PE.

And, most importantly, are you thinking that any of the water parameters might be suspect in my poor coral's condition? :-( My first guess would be that the condition of the coral is due to sub par water parameters. My next thought would be what temperature and temp fluctuations does your tank exhibit during the day. Large temp swings can severely effect corals...especially LPS. And my final thoughts would be:

how old is the coral in question?
Where did you get it?
How did you acclimate it?
Did you do a coral dip on the plate?
How old is your tank?
What lights is it currently under/was it under before purchase?

 

[Reef Bass]

With your ca being way low, I suspect your alk is out of whack as well. IMHO, one has to keep an eye on one's alk level always. Aside from the most basic temp and salinty measurements, I think alk is where many people stumble. I like the 7-9 range. Significant fluctuations in alk of more than a point a day are likely to cause issues as well, depending on the corals kept.

 

[dtesenair]

Wow. That's a lot of information (and questions)! Okay, here goes...

Alkalinity - Thanks for the info. I'll pick up my own test kit this afternoon and start keeping track of that parameter.

pH - I've always heard about the reverse photo cycle but never understood why. Thanks for the explanation! I do have a refugium and can adjust the light timers with ease.

Salinity - Interesting observations. I'll start topping off slowly with salt water until it raises to that level.

how old is the coral in question?
Where did you get it?
How did you acclimate it?
Did you do a coral dip on the plate?
How old is your tank?
What lights is it currently under/was it under before purchase?

I've had the coral about 6 months now and it has been doing perfectly fine until 2 weeks ago (or so). I got it from my LFS. I acclimated by floating the bag and slowly adding my tank water the the bag. MY tank and the LFS were very close together in parameters at the time. I don't remember if I did a dip on this specimen or not. I usually do, however, and I use CoralRx. My tank is about 1 1/2 years old. I do approximately a 15-20% water change every other week. The tank lighting is a Coralife 4x54W T5HO fixture.

I have noticed over the last few days that the receding seems to have slowed or (hopefully) stopped. Perhaps it got injured by a hermit crab or something. Is that possible?

 

[RokleM]

If you're adding "pH buffer", that's probably alk solution and could be making things even more out of whack. Test and report back. As well, swinging pH is very normal and often a long step of troubleshooting many focus on when it has a very minimal impact. As long as swings aren't large (more than .5) or pH is very low/high, I'd ignore it.

As well, I agree on alk being important. With stonies, it can be readily absorbed, faster than many realize.