Too much light?

[whiteshark]

I am pretty new to SPS corals and have a question reguarding the placement of my monti digi. It is probably about 10-12 in. from a 150 W 10k DE MH. It looked pretty well for a few days, but now the tips are turning white and some polyps are dissapearing. At first I thought maybe it was growing, but it now appears to me that the polyps are just receding. (sorry no pic)
I don't believe it has anything to do with the water params as 3 other acros and a monti cap are doing very well. Could it be too close to the light? I know they are one of the less demanding SPS, but I thought scince the light was only 150 W, it would be ok near the top.

Any help is appreciated!

ammon- 0
trite-0
trate- 5ish
phate- .5 (working on that)
pH- 8.3
Alk- 8.5
Ca-450
Mag-1350

 

[Jeremy Blaze]

I would not think it is too much light, but what kind of lighting did it come from?

 

[whiteshark]

I believe a SE 175W 14 or 20K

 

[zoazoa]

Move light upper around 13-15 inch..
10K is much brighter but also has much more UV than 14K or 20K.

 

[Ti]

Is it growing upwards?

 

[whiteshark]

It is growing both upwards and outwards. It is just a frag. It has 3 sections growing up, and the base seemed to be growing out. However, now along the perimeter of the base and the tips of the upwards growth the polyps seem to be receding. I am thinking the light may just be a little too bright. I will try moving the frag down a little.

Any other suggestions are appreciated! Thanx!

 

[Ti]

seems a LITTLE too bright, but nothing too loose sleep over

 

[Ralistin]

The big question is what was the par it was under and what is the par it is under now?

If a frag is under a 20k bulb with lower par and then placed under a 10k bulb with significantly more par then the coral must adjust to that. If it is a big difference then the coral may bleach. It is up to you to gradually adjust the coral to the new lighting assuming that is the issue to begin with.

 

[whiteshark]

^ That was my thought. I'm sure the PAR is significantly higher. I thought it would be ok as 150 W is not that much. However, I guess it was too much PAR too fast. I will move it lower in the tank and move it back up gradually.

Thanks again for the help!