What's wrong with my coral?

[Jakepen]

Tank is 8 months old

Alk between 8-9.5
Calcium 440
Magnesium 1300
Phosphates undetectable
Nitrates 2ppm (Finally have nitrates)
Temp 79
Lighting is two kessil 360s ran at 55% intensity, over my 3 foot tank.

Over the weekend we were away, and my house dropped to 50 degrees. Tank was 71 when I got home. (Lesson learned, keep the heat running when we go away.) I've also been feeding a bit more heavily, to get a reading of nitrates. Today my coral is very blah, it either looks bleached, enchanita (spelling) looks very dark when usually bright orange. My jack o lantern is not bright like it usually is, almost transparent, rainbow monti has zero polyp extension. My frogspawn looks a bit bleached, also another is not extending like it use to (it gets with constant flow, same direction, I suspect it doesn't like it). My favite is turning white in a few places, also not sending out its feeders. What should I be testing for, or looking for? Any ideas I appreciate.

 

[Reeferdood]

Well,
For starters that cold snap did not do you or your corals any favors.. I would not go do a bunch of things to your water except slowly bring the temp back to normal and keep it stable. Looks like the corals have frostbite, they should bounce back..
Good luck and invest in a heater if there is ever the possibility of another cold snap on the horizon..

 

[Jakepen]

Well,
For starters that cold snap did not do you or your corals any favors.. I would not go do a bunch of things to your water except slowly bring the temp back to normal and keep it stable. Looks like the corals have frostbite, they should bounce back..
Good luck and invest in a heater if there is ever the possibility of another cold snap on the horizon..

That's common for coral to get "frostbite"? And I have a heater, you mean a heater for my tank right?

 

[Reeferdood]

Not common at all, most tanks won't see those temps.. Where do you live?
Yes, a heater for your water.

 

[cloak]

Has anything else changed besides the cold snap? The corals should be able to endure this drop in temperature IMO just as long as it didn't happen in the blink of an eye. Have you been fiddling with your lights at all?

 

[Salty1962]

If your tank parameters are where they need to be, the corals should recover with time. I had a controller issue that caused my tank temps to dropand the corals recovered in a couple of months. Good Luck!

 

[Jakepen]

A couple of months recovery!? That's a bummer. I live in Michigan, I have a heater in my tank. I think it was just so cold outside the water, the heater couldn't keep up with the dropping temp. I adjusted the light from 50% to 55% probably a month ago. Other than that nothing new, I did start dosing vibrants aquarium cleaner, to try and rid some algae. Paramaters stay relatively stable though, weekly water changes.