New frags bleaching/color loss

[Formulator]

Im looking for some help identifying the cause of color loss in the tips of a few coral frags that have been introduced in the past 2 months. The problem started when I replaced my lighting with a new fixture, so I want to think that it may be due to excessive light intensity, but I was under the impression that sps like my anacropora thrive in high lighting.

Im running 2 250W metal halides 8 hours/day with 4 t5 actinics for 11 hours/day. The light is about 6-8 inches off the water. Also, since adding the new lighting, im losing the coraline algae on the back wall of the tank. My alk was down a bit at 6-7 dKH but ive brought it back up over the last week to 9-10.

Tank info/params:

125g display
50g sump
4x koralia (2x 600, 1x900, 1x450) for flow
Skimmer always running (rated for 200g)
Carbon
GFO

PH 8.3
Salinity 1.025-1.026
Temp 78-81
1-2 ppm nitrate
430 ppm Ca
9-10 dKH alk
Not testing PO4 currently

 

[Formulator]

Not letting me upload more pics, but basically 2 other corals have similar whitening at the tips, but polyps look happy.

 

[Annap729]

1)Acclimation
2) dropping to 6-7 absolutely will bleach, at least in my experience.
3) lighting-id ramp up over a 30-day period.
$.02, I'm sure others may have other thoughts


Sent from my iPhone using Tapatalk Pro

 

[fishkeeprian]

Hi yes they do like high lighting but with any coral you do have to light acclimate them. I would do this as you have changed your lighting, start it off on the sandbed the move up gradually. If it is light damage them taking it down lower will give it a chance to recover. I would really get a phos test kit as high phosphates can brown sps.

 

[ca1ore]

Coral in that one photo looks dead, not bleached.