bleaching question

[MU8ST7ANG]

I have a tricolor acro and a green birdsnest that have turned white over the past week. There are still polyps on both and they appear to be growing still. How do I get the color back in them? Why did this happed?

 

[MU8ST7ANG]

This was blue and purple last week

 

[Jcurry@wesketch]

It looks like they've expelled their zooanthelle. This usually happens whe nthe coral is stressed. Did you change something on/in your tank recently?

 

[MU8ST7ANG]

Nothing has changed except the temp has been 79-83 and the sal went up to 1.3 which im trying to bring down now. They were in my tank for about 6 weeks and looked great

 

[MU8ST7ANG]

That was 1.03 but I have it down to 1.027 so im trying to get it to about 1.022

 

[Jcurry@wesketch]

Nothing has changed except the temp has been 79-83 and the sal went up to 1.3 which im trying to bring down now. They were in my tank for about 6 weeks and looked great

That will do it. That temp range probably stressed out the corals. SPS corals are more sensitive to temperature swings than most soft & LPS corals. I try to keep my tank between 76-78 degrees. If my tank reaches 78 I turn lights off since corals can handle less light better than high temps.
The salinity of natural sea water (NSW) is around 1.026 so you might want to use that as a target. 1.022 is better for fish only tanks because it helps keep parisites and infections in check, but is not recomended for corals.

 

[MU8ST7ANG]

So I went and picked up a 7" desk fan. Wow what a difference the temp seams to be holding between 77-80 rather than 79-84 I hope this helps.