Dying Reef?

[DLART89]

Hello all,
I have a 46 gallon BF reef tank that contains (or did contain) the following -striped mushrooms, a large toadstool, finger leather, star polyps, green button polyps, yellow polyps, feather dusters, misc. mushrooms, 2 clown fish, 1 yellow damsel, a sea urchin, and several misc. "clean up crew" critters. Over the last 3 months, my metalic green star polyps which were growing in a large mat have all but disappeared, the yellow polyps have been dying off, and my 2 feather dusters have died. Also, the coralin algea that used to encrust my liverock seems to have gone away also. The tank has been set up for 2 1/2 years now and I have never had any problem keeping corals healthy and happy until now.

I do water changes as follows - 5 to 11 gallons every 3 weeks.

I have pc lighting (2 55 watt super daylight and 2 55 watt actinic) that stay onabout 10hours per day.

The water parameters are good as far as PH, nitrate. I dont have a kit to test calcium levels.

The only additives I use are - Reef success (Calcium +3)
Coral vital LSB and Coral Vital (dosed after water changes)
If you read this and have a suggestion, please help!
Thanks

[saltjunkie]

when is the last time you have changed your lights?
has your water sorce changed?
have you added any new rock, or critters that you might not have known what they were?

[saltwaterdave]

The first thing that came to my mind was when was the last time you changed your bulbs?They lose intensity as time goes by and need to be changed on a regular basis.My experience with pc lights is they do not last very long.

[saltjunkie]

also, have any new cleaners or pesticides been used around the house?

[DLART89]

The lights were changed mid-October. No pesticides or anything like that either.