Coral dying - any ideas?

[IPT]

I've had this yellow ridge several months. I have added nothing new to the tank in many months either. Suddenly three days ago I notice these polyps dying with what looks like erosion around them. My Ca has been low and I hastly increased it by 10-15 PPM (it was 330 and has been under 360 for a while - I know, way to low but my ofther Acros and SPS are growing well). I have been running high Alk (11-12 DKH), mod ca and was just about to start going with the inverse. In recent weeks I was actually noticing that the yellow living structure was finally starting to fill in some of the dead skelaton that was there where I bought it. I thought it was thriving, now this? Could that Ca jump have done it? About a week before I increased my flow too but it is indirect and I could only imagine would help. First photo post so bare with me if I messed it up....

 

[latazyo]

I think you wanted "new thread"

 

[IPT]

Dude - my computer is wigging. Disregard- "yes", I thought I was in a new thread! Here is a pic of my 20Long top down. At the time is was running with 3 65w CF's. It did well and I was even growing some Acro frags. Noticable growth, though I would upgrade to T-5's if I were you (I did, but I am also upgrading to 50 breeder). Sorry about the mis-post.

 

[IPT]

Here is an Acro growth shot. It has been under T-5's about a month now, but it grew with the CF's. It encrusted the entire base of the plug. Montipora are fast growers. Plating types (Monti Caps) would use horizontal and not vertical space. Maybe some table acros. Allowing for growth of any SPS you won't fit all that many in a 20 though.

 

[smiller]

I split this thread off from the other one.