Coral Bleaching?

[orion]

Help please!

Over the last two days I noticed these two corals bleaching. I’ve had them for almost 10 years but have not seen this happen before.

So far all other corals, clams, and fish are fine. No signs of stress or bleaching on my LPS corals.

I first noticed a small part bleaching two days ago; it has progressed into this today.
<img src="http://www.photodump.org/stored11/Bleach1.jpg">

This happened today; I noticed it loosing some color yesterday but was white when I got home today.
<img src="http://www.photodump.org/stored11/Bleach2.jpg">

Two polyps on the right fell off yesterday as well as one in the lower left. One in the center left is dieing today.
<img src="http://www.photodump.org/stored11/Bleach3.jpg">

PH: 8.35
Calcium: 420
DKH: 8.5
Phosphates: 0
Nitrates: 0
Nitrites: 0

Recent changes:
A few weeks ago I added emerald green crabs and more snails. I’ve been dealing with cryo and other green algae’s which I noticed were dieing off rapidly over the past week. The only chemical change I made in the last two weeks was adding prestone driveway heat as a calcium supplement. I’ve only dosed it twice and was about 6 teaspoons each time. I normally dose b-ionic at night. I also changed my phosban and carbon last weekend. I also added a capful of seachem iodine.

If anyone can offer me some suggestions I’d really appreciate it.
Thanks,
John

[Tang Salad]

Your numbers all look fine. Have you had any temperature surges recently?

[orion]

I did lower my temp controller from 80 to 79 recently. My temp use to fluctuate between 79-81, now between 78-80. I did change it back to 80 today. Do you think that could be the cause of my problem?
Thanks!
John

[Tang Salad]

No, that temperature range is fine.

Sorry, that was my only guess. :( Maybe someone else will come along with another idea.

[Frick-n-Frags]

hmmmm, both are Turbinarias...... hopefully it isn't some weird specific disease or trace shortage etc.

dang, I didn't know you could hurt them. they can live in the dark covered with silt. It's some kind of new physical stress, gotta be.

what would I do?........hmmmm....

1)check for stray electricity or external poisoning source. at some point a pH or heater can finally start leaking. a piece of poison metal may have fallen in, someone fabreezed to close to the tank etc etc etc
2)grill the other occupants of the house like they were bin laden
3) make triple sure all my measuring stuff is really calibrated, maybe double check your water somewhere else ASAP
4)mega-, no F'n around on this one, water change = only shotgun approach that can buy you time = best option when all hell is cutting loose and you don't know what it is.
5)frags to friends to get back later if the worst happens(although, both are very common, but hey...)

6) meditate, a lot, on the concept of: "what in the sam hill is now different"

best of luck


edit, upon a reread here:
can you tell me what the complete 100% chemical composition of that prestone sidewalk melter is. I would guess 80% CaCl)2, but howabout the other 20%???

that's the kind of stuff that can tip the scales on a weakened system, like let's say getting close to needing a good cleaning. Not saying yours is, just creating examples.

[orion]

Frick-n-Frags
Thank you so much for the detailed response. I have had problems with stray voltage in the past which I thought was caused by my Sedra 3500 euroreef pump. It was replaced over a month ago. At the time I removed my ground probe since the voltage was gone. I noticed more stray voltage a few weeks ago and could not determine the source, so I installed the ground probe again.

I spent the entire day trying to find the voltage and as easy as it should be I was unable to find the exact source. With everything disconnected from the tank I still read 5 VAC from the water to ground (copper water main). With everything running I read 30 VAC. If I disconnect my sedra pump it goes upto 40 VAC. I tore everything down today / all electrical connections and cannot believe I can’t find the exact source. It seems to be a combination. I will continue to search for the source. If I install the ground probe it goes to 0 but I’m not sure if I should continue to use it since it was one of the changes I made before the corals started bleaching.

I tested the water again today and here are the results.

Salifert Reading Color

Ammonia <.5 White
Nitrate 0 White
Nitrite 0 White
Calcium 420
KH / ALK 8.6 / 3.09

Hatch PO-19 PO4 Test Kit
Phosphate 0 Clear


Voltage:
Everything turned ON: 35 Volts AC
Everything unplugged: 5 Volts AC
Just Sedra Pump OFF: 44 Volts AC
Just Main pump OFF: 44 Volts AC

I started unplugging devices one at a time:
Pumps OFF: 40 Volts AC
Temp Controller OFF: 40 Volts AC
Lights OFF: 43 Volts AC
PH Monitor OFF: 44 Volts AC
Float Switches Disconnected: 44 Volts AC

Everything unplugged: 5 Volts AC

What confuses me is I’m running a PLC to control the electrical devices in the tank. With All Pumps, heaters, float switches, lights, probes, etc completely removed from the tank I read 16VAC when the PLC is turned on. When I’m reading this there is no electrical connection to the tank at all, everything removed. I’ll need to tear into that next and ring out all the wires to make sure nothing is crossed.

Thanks again,
John