Help! Why is my Monti Digitata bleaching?

[webdr]

Its been doing very well for almost a year and lately the polyps have become light pink and the skeleton has bleached. Its still alive but looks pale.
A little about my system.
lighting 150 watt 20,000k hqi coralife aqualight. The bulb is about 8 mos old.
2x55 watt full actinic PC
The digi is a little below midway in the water column....closer to the bottom.
should he be closer to the light? time to change the MH bulb? Different kelvin?
Im lost! Look how beautiful it was a few months ago!

I will also add that my acro, monti capricornus green and red are growing very well....they are a little higher in the tank though

[Justin]

Two things immediately come into mind from my own experience. My digis were excellent monitors to when to change my bulbs and have been close to yours, but thats gonna be a tough turn around unless you find some stuff out quick. If it was a brown out Id suspect phosphates, but in your case my hunch is on the lights.From what Iv'e gathered the 20k's typically need changing more periodically then the lower kelvins like 10 and 6k's but I've heard this through the grapevine and have nothing to back that up. But as a general rule of MH's they need changing from 9-12mo. anyway. Not to say they cant still keep things alive, but it's repracussions are exactly the same as what your witnessing now.Best of luck, I know its nerve racking.

-Justin

[Geoff]

have you been fragging it a lot? the pics do not seem to match. the healthy one looks larger than the bleached one. how long apart were the pics taken?

have you had any temp spikes lately?

G~

[JennM]

What's your temperature running these days? Overheating can cause bleaching.

Also, do you use carbon? Chemical warfare between corals can cause one or more to fail.

Jenn

[Hardhead Cat]

I agree with every one - I would check: phosphate levels, heat levels, carbon "freshness" - and replace bulbs.

HHC

[webdr]

yes it has been fragged a little and I accidently bumped it and knocked off a few branches a few weeks ago.
The temp has fluctuated a little bit cause I have been fiddling with the heater alot lately.
Ive been running a phosphate reactor so I dont think phosphates are an issue....
Im going to change the bulb to a 10,000k, set the temp at 79 and try to maintain it...
you dont think he is too low in the tank do you?

[Geoff]

when was the phosphate reactor put on? where is the return for this compared to the coral that is bleaching? why do you have a phosphate reactor? what media are you putting in the phosphate reactor?

G~

[webdr]

Ive been running the reactor for a few weeks....reason being, I use the aquarium pharmaceuticals tap water filter (an ro/di is next on the list) and I feel the phos reactor is a piece of mind. I know the tap water filter is not the best, but it works well for the price and Ive been using it for a few years and the digi just started to bleach now.
The output is at the top of the tank going across from left to right so not really near the coral in question
Im using Tunze Phosban.

Im going to add that I have a smaller green digi that has done the same thing but not as bad...

[skeety]

the newer pic...well...it looks like it's REALLY in the shade, so to speak.

Sure it's not blocked from light?

[webdr]

It looks worse that it is, but it still is not getting full light. The second pic was when I turned on the MH last night after lights out and took the pic before the light fully warmed up.
Heres a theory.... I have an engineer goby who digs like a mad man.
He has dug so much that the entire tanks live rock has settled a few inches and the rock that the digi is attached to has rotated down, the light is not what it used to be. Im going to do a little aquascaping and see if I can get him in the light a little more.