Reviving bleached coral

[Zero Nitrates]

So you have bleached a coral in your tank. Thus could have happened by a number of ways.
When a coral is stressed it produces super oxygen radicals and hydrogen peroxide that damage the zooxanthellae and also expels zooxanthellae into the water column.

Do you leave everything alone in your tank and hope the coral recolonizes the zooxanthellae or do you stop using your protein skimmer(if you run one) in an effort to keep the free floating zooxanthellae in the water column until the coral recolonizes.

 

[melypr1985]

While you've named ways it happens, there are reasons behind those ways. My first thought would be to test my water and see what the reason was.... Make corrections if needed, then sit back and wait. I never thought about the skimmer taking the zooxanthellae out of the water though. Good question! So here's one to play off yours.. Once a coral expels it's zoox can it come back to the coral or is it the zoox that's left in the coral that just repopulates? The answer to that, would determine if it matters to have the skimmer on after or not wouldn't it?

 

[Zero Nitrates]

When most coral reproduce in the wild, they do not have zooxanthellae in them to start with. They get the zooxanthellae from the ocean water.

 

[mcarroll]

So you have bleached a coral in your tank. Thus could have happened by a number of ways.
When a coral is stressed it produces super oxygen radicals and hydrogen peroxide that damage the zooxanthellae and also expels zooxanthellae into the water column.

Do you leave everything alone in your tank and hope the coral recolonizes the zooxanthellae or do you stop using your protein skimmer(if you run one) in an effort to keep the free floating zooxanthellae in the water column until the coral recolonizes.

There's an article called "Is the coral-algae symbiosis really ‘mutually beneficial’ for the partners?" by Wooldridge that looks at this and is very interesting IMO.

 

[Squamosa]

I have taken acropora frags in my system at one time and bleached them with Zeospur (it is said copper is an active ingredient in this) and the results were striking, white corals, including white polyps!

This was done to remove any unwanted (brown, if any) zooxanthellae and to see if any underlying colours would show themselves,possibly becoming dominant.

After ~2 months the corals were back to their original colours, which I might add, were not brown and that was the last of that little experiment.
The tank ran as always, with all filtration, including skimmer, on!

 

[thabizness]

I had a slight bleaching event in my tank recently. For some reason the schedule on my lights were acting up and stayed on full blast overnight a couple of times. The result was a minor bleaching event on some of my acros. I did still have polyp extension. What I did was reduce the light schedule and started dosing acropower and spot feeding reef chili. It also was the same time I started to dose nitrates because I always read 0. After a few weeks color has started to return. Not back to where it was but I'm happy they pulled thru.

May not work in your situation but this did in mine. I didn't loose any acros.

 

[Zero Nitrates]

@mcarroll That is a great read. Thanks. I never would have considered zooxanthellae as being farmed by the coral

 

[Kungpaoshizi]

Whether it's bleaching or necrosis, feed more. I've saved numerous corals by feeding a ton of nutricell or reef energy(which is on a doser anyways). I'm to the point now where I'm losing track of just how many corals I've got from the LFS or buddies that are half dead and I've been able to bring back to full health.. My gf calls me the coral whisperer.. heh