tonga branch turning white next to featherduster

[serg11]

I got a featherduster 2 weeks ago and my tonga branch near featherduster is turning white. i got mushrooms, zoos, 2 clowns, watchman, t-5 in a 30 gal. I did noticed the first couple of days the featherduster was releasing this dark slime from its center. salt 1.024, nitra 5, ammon 0, nitri 0, ph 8.4, alk 7dkh, cal 360, phos 0. any thoughts

 

[cannonman]

How long ago was the tonga added? I don't think that the feather would have anything to do with the death of the purple coraline algae.

 

[serg11]

tonga branch has been there since the day I set up the tank, 10 months

 

[cannonman]

You don't have a sea urchin in there by chance do you?

 

[serg11]

no sea urchin just snails, hermit crabs and I do have 2 black sea hares ( slug looking thing which were hitchhikers since day one). I did use red slime remover 2 weeks ago. I had some red slime build up on my sand bed. I believe it was from t-5 156watts upgrade 2months ago. and I reduce my lights to 8hrs a day. slowly increasing back to 12hrs for the next month or two.