Kenya Tree Coral Dying?

[Shackleton]

Whoa! My Kenya Tree Coral has been a happy camper for years. Over night it turned nearly black and shriveled up. Everything else in the tank looks good. No major changes to water quality or setup. Only thing new is I added Sea Lettuce and Red Ogo to the sump, but I can’t imagine that’s a problem. What’s going on?
(Before and after pic)

 

[Biglew11]

Water parameters? more specifically nitrate and phosphates. you added algae to the sump, you didn't drive these to zero did you? nitrates around 2.5 to 10 ppm phosphate around .03 to .1 ppm

 

[Deyan]

They like nitrates and phosphates- check that! Make sure flow is good too. Cheers