Monti cap bleaching

[Silverni2]

I've had this monti for over a year and have fraged it several times it is now bleaching for no aparent reason. It's been in the same spot and has encrusted itself on two rocks. I have 2 acan fixtures 104, they get to about 75% lit, could that possibly be to high or maybe to low?
My parameters have been the same
alk runs between 8-9
calc410 - 450
mag 1350- 1500
no3- 1 ish elos
phosphate barely see blue on a salifert kit
my temp this time of year runs 75 to 77.5
I don't run a heater
I have noticed crabs hanging on it from time to time
I have another piece of the same green monti on the othe side of my tank which is doing well
thanks

 

[duke62]

re check your alk.i was told that swings in alk will notice caps bleaching first

 

[jerl77]

check for Monti Nudi you add anything new to the tank ?

 

[Silverni2]

Adding new stuff all the time! What is a monti nudi can I see it during the day only at nite? What do they look like

 

[rebelson]

Adding new stuff all the time! What is a monti nudi can I see it during the day only at nite? What do they look like

http://www.melevsreef.com/pics/05/11/monti_nudi14.jpg

 

[rebelson]

Did you dip your new arrivals prior to adding them to your tank?

 

[Silverni2]

Just googled the nudi I'll look for it/them but I don't think so. I'm going to use some coral tip on it tonite. I think duke might be correct with alk flux, it's time for me to invest in an auto doser!!!

 

[Silverni2]

Rebe I usually do but I picked up an acan that I put in without dip this weekend and I didn't have time to dip. Be sure nothing will go in the tank anymore without dipping first.
To much at stake!!

 

[jerl77]

dip dip dip dip dip

 

[Josh]

Retest the alk as already stated.

Your temp is quite low btw.

 

[charliethetuna88]

dukes right alk swings def mess up montis