White coraline ??

[jjflounder1]

My systems been running about a year-and-a-half ..
Recently I've noticed this "White Coraline" on the glass ... Some odd small white spots on the rocks ...

My question is... is this really Coraline or some other calcium deposit ?

 

[Scotty Buttons]

Coraline algae usually turns white when it's dead. ;Dead

 

[jjflounder1]

I know my alkalinity is down to 7 ... I ran out of part B ...
I'll have to keep an eye on it's "growth" pattern ...

 

[Jr'sReef]

When my alk drops I start getting this. It’s coraline that’s dying. I get blotchy spots on many covered rocks as well.