Old Clam having problems

[Tasmanian]

I have a maxima clam that I have had for about 3 years. It was about 2-3" when i got it and is about 6'7" now. For about a week it has begun to close up more and more throughout the day and now it is basically closed.
Some background:
For the first 1 1/2 years it was under Compact Lighting (and lived-go figure...didn't grow much during that time though). For the last year and a half it has been under T5's.
Within the last two weeks I changed out my bulbs. It was time and I wanted more blue so my corals would pop. I have 6 80W bulbs that are overdriven with icecaps. I followed as closely as I could Grim reefers suggestions and ended up with the following configuration:
ATI Blue Plus
ATI ProColor
True Actinic
12000K Aqua Blue
ATI Blue Plus

At about this same time i added a new baby maricultured Maxima.
I placed this one on the rocks. The big one was on the sand.
The baby fell everyday for three or four days and then wasn't happy anymore. He is closed up and I thought probably dead. But I just took him out to see and he wasn't attached to the rock but he doesn't smell and he slowly closed up a bit more. So I put him back in higher up on the rock.

Also about the same time I changed out my phosfar. But I didn't have enough phosfar so I only added enough for 125 gallons. my tank 270 total gallons.

Nitrate 0
PO4 0
Cal 420
Mg 1200
Ph 8.22
dKh 7 ( I've been fighting this for a year...can't seem to get it up)

Two days ago my clam released his foot as if he was going to move. Thinking it is a lighting difference I just moved him up about a foot onto the rock.

Any ideas what else may be going on? Do clams recover very well once they start to decline?
Thanks and sorry for the ramble but I wanted to give you all the info I could think of.

[Tasmanian]

Just read my post ! OOPS! The clam is now about 6" or 7"...not 6 feet 7 inches!

[quicksilverq]

could you post a picture

[skinz78]

I am thinking it has been light shocked. Try placeing a few layers of window screening over the clam to shield it from the light and see what happens.

What fish and inverts do you have?

Also a pic would help alot.

[Tasmanian]

http://reefcentral.com/gallery/data/500/92375clam_day1_4x6.jpg

Here is the clam right after I moved him off of the sand onto the rocks.

[Tasmanian]

http://reefcentral.com/gallery/data/500/92375clam_day2_4x6.jpg


Here he is the next day (today). He is much more retracted and looks horrible.
I thought it might be light also. But I thought he might not be getting enough light. Prior to my changing the bulbs to mostly ATI Blue Pluses I had him under the same 80W T5's for a year and a half. Only those T5's had more bulbs in the daylight range. That's why i moved him up about a foot onto the rock yesterday.

[Tasmanian]

http://reefcentral.com/gallery/data/500/92375clam_day2_4x6.jpg

[Tasmanian]

I also think it's weird that I have this clam for a few years with no problems and great growth. Then I get a new clam and within 2 weeks they are either dead or dying.
I got the new clam from a reputable dealer. The new clam was quarantined and inspected prior to placement in my tank. I still haven't seen anything odd.
Maybe when I placed the new one in my tank my fish finally saw clams as food and messed with them
????

[mbbuna]

what fish do you have?

[Tasmanian]

4 fairy wrasses, skunk clown, blue damsel, sailfin tang, chevron tang, tomini tang, and an anthias

I did have a niger trigger in there for quite some time (4 years). I removed him about a week and a half ago because I saw him messing with my linka star. I thought he may have messed with my clams. But they only got worse once he was removed. Before the trigger was removed my big clam did look like one little spot may have been messed with. The clam got progressively worse after that. Once they start to decline do they come back around very often?

[mbbuna]

what product are you adding to try to raise your dkh and how are you adding it?

[Tasmanian]

Dosing Randy's Two Part and also adding Kent marine Coral Builder. I dose the 2 part with a dosing machine on a daily basis. The Coral Builder I do randomly-generally whenever I test the levels--maybe every other week.

Another monkey wrench-- I just decided to change the carbon out again. I run it in a canister filter out of and back into the sump. After changing out the carbon the canister isn't running/pumping anymore. I know it was working about 3-4 weeks ago. Today I unplugged it to change it out and I'm not sure it was running. I would think I would notice it, but maybe not. If it wasn't running and I changed out the Phosar could that have leached out enough iron to do this? Keep in mind I only had enough Phosar for half of my tanks water quantity.

[skinz78]

Do you have a before pic?

I think that is a squamosa

[Tasmanian]

Sorry no pic from before. He was always super open and beautiful. It may be a squamosa. I just did a quick read to see how to tell the difference but I still don't know how to tell. Is there a quick identifier? he is brownish with big purple spots and he has scales or plates on his shell.
He's not doing any better today.

[Tasmanian]

skinz78, mbbuna, and quicksilverq,
thanks for trying to help....unfortunately both clams were dead this morning. I still wish I knew what happened. I would like to have a clam in the future. But if I don't want to repeat whatever I did wrong.