Purple Slime on coral?

[kalani]

I noticed a small section of what looks like a purplish looking algae or slime on one of rocks corals. I know its not coraline. Do you guys know what that could be? Is it harmful? Where did it come from? TIA

 

[CBRGuy]

What king of coral is it. Most LPS will put a mucus. Sometimes it is a sign of infection but maydo it when they are heathlt too.

 

[kalani]

It's a dead bleached coral. There's green algae growing on it but the purple looking thing looks like a slime of some sort. I'm charging my camera battery to take a pic and post it. My LFS said it could be because I might have traces of metals in my water. Just wanna make sure thru you folks before I buy anykind of water conditioner.