Brown is the color that absorbs light first. So definitely lighting would be my first thought. I don’t know how strong your desire is to try and change things, sometimes changes make it worse.
However if this is a good time to change your light bulbs I would try that first. And you are already on top of your water quality so lighting would be my choice.
I dont know though what K you have now and what K color to get in order to make it change to the original, because it would be impossible to duplicate the original conditions that clam was in.

I feed it live phyto every second day as it was very small when I got it. Now it's a bit bigger but still a small clam.

Should I stop feeding it phyto so that it develop more zoo on its own?

I put a crate under the light on the spot to dim the light a little. Seem that my maxima has more powerfull colors and more brown at the bottom of it where the light does not fall directly and it has also lost its brown color on top where it gets direct lighting. hhmmm.. I thought clams were loving strong light? Both clams are side by side.

I just took a pic of my maxima and that makes me realize the maxima is having the same issue, here is a pic of the maximum when I got it:

http://i786.photobucket.com/albums/y.../104_2171s.jpg


and now:

http://i786.photobucket.com/albums/y.../104_2362s.jpg

So it is also gong pale in color and washed out. :(

I know you're disappointed . . . but those are really lovely, healthy looking clams. I'm pea green with envy. I'm afraid to purchase any, as I'm very worried about pinched mantle.

I agree, they are very beautiful clams, either way. I see what you mean about the brown, it def changes the overall appearance. I have 1 clam, it's blue green and has grown quite a bit but it's not as nice as yours. Good luck, I can't offer any advice.

Like the others..i like them even more after the morph.I would kill to get that kind of water testing done.

I had a maxima yrs ago that started loosing color and ended up was pyramid snails infecting the clam. Was a real pain

No pyramid snails that I can see and I checked at night.

I know they are a pain to get rid of.

I have put a crate over the clams and at least the maxima seem to be getting darker in color with more brown apparent. It is a very small difference so maybe I am just imagining thing. I will see. I will check again tonight for snails with the magnifying glass and led light. Also the clams are not receiding at all, they extend fully and seam very healthy.

When I had clams awhile back I had quite a collection, the first pic you posted the people are calling brown and teal, I'd like to refer to as gold and teal... Anyhow those ones were my favourite clams, I had them blasting under 250w hqi mh 14k and they held their colours and patterns well. The ones that were at mid tank seemed more fuzzy in the patterns and dull in colour.

You stated that yours did not like more light and it was smaller, mine was about 2.5-3" mantle so they weren't the smallest however weren't considered large either. My suggestion would be if possible to try and raise them abit over time so they are acclimated to the light. I am willing to bet that more light will infact bring back the gold patterns..... Good luck!

clam
 

what phyto are you using.clams would probably want isocrysis for the omega fatty acids or maybe tetraselmius

No it's quite the opposite. The parts of the clam that receive less light is a lot more colorful. The part that is receiving direct light is getting dull.

I actually covered the clams with a bit of crate and they are getting better, at least the maxima seem to be regaining a bit of saturation in the colors.

Mine are probably too close to the light or maybe I keep my light on too long. I was using 12 hours per day and I cut to 11 hours per day a few days ago.

I am using live phyto. I was using DT but cannot find that anylonger, so now using Reef nutrition live phyto.

http://reefnutrition.com/phyto_feast_live.html