Montipora's not showing full PE???

[spankey]

Is there a reason why montiporas would all of a sudden reduce PE during lights on?
My Rainbow and Superman monti are the ones showing the signs. My Undata and digi's seem OK.....
I changed my bulbs from the 14K phoenix to ushio 20K's. The reduction in par shouldn't have done this I wouldn't think. Allot of the corals have colored up incredibly from going to the 20's.
My temp is at 79 degrees
Calcium 450
DKH 9.2
PO4 Salifert 0 (do not have a colormeter)
No3 0
Magnesium 1400
Flow has Not changed nor feeding or water change regime.
Has anyone seen this before? It seems at night the polyps are out more than when the lights are on?
Thanks
Spankey

 

[myzislow]

"It seems at night the polyps are out more than when the lights are on?"
Well, that is normal for all SPS corals.
Are you sure you don't have any fish that have taken a liking to the taste of montipora? Definitely keep an eye for nipping. This may explain why you are seeing increased PE at night in the affected corals compared to day, as there could be fish bothering the corals during the light hours.
How long ago did you switch your bulbs? They could still be adjusting as well. You parameters are great so I doubt it's water quality related.

 

[spankey]

Well it appears there aren't any fish nipping..... The monti's are responding to the new bulbs. They are about two months old. They are turning so blue (skeleton) it's crazy. I just don't know why all of a sudden they aren't showing much PE like they used to?
I will keep an eye on them though. I guess time will tell.
Thanks for the reply!
Spankey

 

[myzislow]

That's good about the fish.
If the base of the coral is coloring up like you said and everything else seems normal besides the decrease in PE then I'd say you're fine and they are still getting used to the new bulbs. I've had my rainbow go up to weeks with out putting it's polyps out for no apparent reason at all.

 

[gatorwpb]

Just because the 20ks have less PAR than the 14k, it could be a specific wave length of light that the 20k has more of that could be bothering the monti.