Can excessive light cause tissue recession?

[Murraydar]

About a week ago I noticed some of my corals (mostly sps) showing signs of tissue recession, mostly at the tips. Other sps are losing quite a bit of color, especially my montiporas. Didn't have any major alk swings and my no3/po4 werent bottomed. I checked my par and it was sitting around 450-500 on top half of the tank. I have a reefbreeder photon v2, apparently its much stronger than I previously thought.

Could this level of light be what caused the damage? I never really saw any 'bleaching', mostly tissue recession. I jogged it down to around 200 par at the top for now, it doesn't look very bright but I suppose I have to trust the par meter.

Any input is appreciated, thanks.

 

[NY_Caveman]

About a week ago I noticed some of my corals (mostly sps) showing signs of tissue recession, mostly at the tips. Other sps are losing quite a bit of color, especially my montiporas. Didn't have any major alk swings and my no3/po4 werent bottomed. I checked my par and it was sitting around 450-500 on top half of the tank. I have a reefbreeder photon v2, apparently its much stronger than I previously thought.

Could this level of light be what caused the damage? I never really saw any 'bleaching', mostly tissue recession. I jogged it down to around 200 par at the top for now, it doesn't look very bright but I suppose I have to trust the par meter.

Any input is appreciated, thanks.

It is certainly possible, especially if those corals were recently placed under that high of PAR without acclimation.

 

[mtraylor]

Yes

 

[jda]

For sure. You cannot fire a Photon up that high without damaging some SPS. 450-500 PAR from a T5 or MH can be OK, but not from most LEDs and especially not a ReefBreeders. I would try and not go much above 300-350 PAR with a Photon V2.

This is likely a quality thing, not a quantity thing.

 

[Murraydar]

Thanks guys. Yeah the light this fixture puts out doesn't seem like much to the eye but the meter doesn't lie. I've reduced it to around 200 par at six inches below the water, ill keep it like this for a month or two and adjust more if things recover.