Bleaching SPS Not Enough Light?

[JVJordan]

Quick Question:

I have only one SPS mini colony of three different species - not sure what they are. I've had them nearly a year with little growth but no loss.

Now I see the colony is bleaching from the bottom up, very uniformly. The upper regions seem fine. It makes me think that the lower region of the colony is not getting enough light.

The colony is about 12" below the surface of the water, and about 20" below a 15 month old 250 watt radium on an icecap ballast that runs about 6 hrs/day.

I don't have a PAR meter so I can't say for sure what it is getting.


Thoughts?

 

[T Diddy]

temperature?

 

[sanababit]

alk?, pests?, sometimes if the colony gives some shade the base of the coral will recede

Sana

 

[JVJordan]

Temp 78-81, alk is low but working on it, pests not likely, I don't have any new SPS additions and this one frag has been in my tank nearly a year.

 

[divewsharks]

Temp 78-81, alk is low but working on it, pests not likely, I don't have any new SPS additions and this one frag has been in my tank nearly a year.

what is your low alk, that could easily be the issue. has it just recently dipped, do you normally keep it very stable? What is your CA and MG?

 

[reefWW96]

if your bulb is 15 months old, that would be the problem. Change it.