What is a bleached nem, really?

[jonnybravo22]

The term "bleached" gets tossed around a lot with respect to unhealthy anemones. I have never learned a precise definition or causes of "bleaching".

What is a bleached nem anyway? An anemone without zooxanthellae?

What causes it?
Is it too much light 'overpowering / burning' the zooxanthellae? Too little light 'starving' these light-loving zooxanthellae?

If too much it would be surprising to me because so many people get bleached nems from LFS / other sources. Doesnt that suggest that all those people who dont know how to take care of nems also have great lighting setups b/c they are too powerful even for light-loving anemones?

What's the deal with this whole bleaching thinng? Thanks!

 

[stykthyn]

there are quite a few factors that could lead to it. in my experience the biggest are-
lack of light and severe trauma or stress. the two usually go hand in hand.

 

[Toddrtrex]

As for too much light, that can cause an anemone to bleach, if too much light is given too soon. An example, an anemone was kept under less then ideal lighting, lets say 96 watts of PC over a 58. And then you go ahead and upgrade to 2*250 watt of MH, and don't acclimate the anemone to the increase in lights, that could very well cause the anemone to bleach. What is actually happening is the anemone is expelling its zoax in hopes of finding a strain that more capable of handling the increase in light.

One way to avoid this when upgrading lights (( or when purchasing an anemone that was under less then ideal lights )) is to use layers of window screening. I have always used 3 layers and removed a layer each 5-7 days.