Darkening SPS - Too Much, or Too Little PAR?

[Rovert]

I have a few frags that seem to have darkened significantly since I got them from the vendors. Leaving aside water parameters, is it possible that my lighting is not quite adequate and the frags are struggling to deal with it? Specifically, I have 2x Photon 32's about 1' above the waterline of my tank; the upper level of my rockwork is about 1' below the waterline, so in total there's 2' of distance from the lights to the frags. All blue channels peak at 65% with red/green at about 10% and whites about the same, but I'm wondering if that's enough. Do you guys think I should bump it up to compensate for the distance?

 

[SilvermistInc]

Darkening frags means an abundance of zooxanthelle. This can be cause by too many nutrients, too little light, or a mix of both.

 

[Rovert]

Darkening frags means an abundance of zooxanthelle. This can be cause by too many nutrients, too little light, or a mix of both.

Very low on nutrients, so it must be the latter. I'll start bumping up the lighting a bit over the coming weeks to see what happens.

 

[SilvermistInc]

Good luck

 

[Mr. Mojo Rising]

Somewhat impossible to advise, with some inches here and percentages there....
The best way is to get a par meter, then you know exactly, with no guessing.

 

[Rovert]

Somewhat impossible to advise, with some inches here and percentages there....
The best way is to get a par meter, then you know exactly, with no guessing.

Understood. I have a Seneye, but need four hands to get it right so my laptop doesn't go for a swim and sleeps with the fishes. ;-)

 

[Perry]

Same fixture, mine 11" above water, acros at the bottom of 24" deep tank colorful and growing.
My peak numbers:
95% blues and UV
15% red and green
30% white
4 t5 bulbs

Edit:
I built up to these numbers over time

 

[TX_Punisher]

I have found my corals darken when no3 starts to,rise in my system. Say above 5-10, and they become darker.

ymmv