Leathers

I've attached two pictures of leathers I take care of, both of which have a band around the base of the coral that seems as though it could be algae. Neither of these corals are doing consistently well. Which parameter being too high or low would cause this? I've only recently been taking care of them, so it's become a whodunit. Params are all in range now. Thanks for helping me figure out what this might be and whether it is an issue.

spiral

 

That brown, kind of crusty looking band on base is normal. All my large leathers have it.

Wonder if it not for some kind of protection against low crawling critters...







Wonder if it may not be something that adds strength to base so leather can stand when gets much larger...:-/

 

It's got an awefully long stalk to it don't it,
the smaller on in hand looks pretty bad but not dead .

I would say keep water quality and parameters on an even keel and you should be fine
leathers will often do that (not open) for periods of time

 

Thanks wild and omard, thats what I had hoped to hear.

spiral

 

my leathers seem to stay closed up if i dont have sufficient flow but yeah most of the leathers i have had have that type of discoloration on their base also.

 

my large toadstool has been in a two-three week "hibernation"...just opening up today...no particular change in flow or other parameter...:-/

 

Leathers and other soft corals have sclerites that give the coral the strength and stability to stand errect!