White pompom xenia not so white anymore

[Fishguy2727]

My white pompom xenia seems to be getting darker and darker. Anyone know of any reason for this?

My guess would be that since it is up so high with good lighting and the water quality is very good that maybe there are more zooxanthellae to take advantage of the light since there isn't much in the water to use for energy. Zooxanthellae is brown, so more zooxanthellae means browner xenia. My concern is it may be instead or in addition a LOSS of white pigment.

What do you guys think?

[kaybee]

There are variants of tan xenia. It's possible that it incurred a xoozanthellae loss while or prior to the place you acquired it from (thus becoming bleached and causing it to resemble white xenia).

After becoming established in your system, with perhaps a more ideal lighting scheme, it has recovered its normal coloration.

'White' (not bleached) pom-pom xenia may transition into shades of gray/blue-gray when they become darker (more of a sign of health deterioration rather than lighting adaption).

The dissolved organic compounds (as the end product of a single fish in the tank and the food provided to it is more than enough to sustain a xenia colony, so I don't think an increase in zooxanthellae is the result of countering decreased levels of water-derived nutrients in the water.

How many xenia's were acquired at time of purchase and did they happen to multiply while still white? Also, have any new xenia formed since the initial group became brown?

[Fishguy2727]

It has grown at about the same pace the whole time. This is what is considered white pompom xenia, also known as Red Sea Xenia sp.

In the Corals book I am still reading they did say that water quality that is very high can actually cause observable negative changes in Xenia spp.

On another forum they said this was exactly what was happening, since this colony is so high in the tank that it is relying more on zooxanthellae and the increased zooxanthellae is causing the browner tint. They didn't say that the high water quality is contributing to it, but did say the light is causing it and to fix it simply to move the colony down, which I will try (at least with a frag) very soon.

Thanks kaybee.

[ILuvMyGoldBarb]

Xenia actually will thrive in water conditions that are less than ideal for many other corals. Xenia species are becoming a very popular choice of use in refugiums due to their ability to reduce nitrate and phosphate. I suspect it is a combo of the lighting and dissolved organics.