Weird pale spots on clams mantle

[mbbuna]

<a href=showthread.php?s=&postid=9301770#post9301770 target=_blank>Originally posted</a> by zuzecawi
Are all of the pigmentations of the clam then caused by zooxanthelle?

no, the zoox are brown, the clam is what produces the bright pigments. when the clam isnt getting enough light it drops its bright pigments to allow more light to the zoox. if there still isnt enough light for the zoox to reproduce faster then the clam is eating them then they slowly reduce in numbers and the mantle gets lighter(fades)

 

[REDDAWG43]

I have 2 MH 250W SE 14K'S on a 46g bowfront tank.
My clam was at the top on the LR and it started to get the same bleachy spots. so I moved my clam to the bottom of the tank and now the sopt are gaining color again.

 

[zuzecawi]

Well, it's stopped hyper extending since I moved it up, so I think you all are right, it must be light deficiency. I started feeding phyto today, we'll see how that works in the future here.

 

[Aquagoblin]

Interesting thread.

I have the same problem with my crocea. It's 3 inches from the surface and the 15K mh (2 @ 250w) heat the water which is what the clams like. I dose DT's Phyto every couple of days.

I'm beginning to wonder if it has something to do with using Phosban and activated carbon.

I keep my alk at 11dkh and calcium at 440ppm with a weekly, 10 percent water change with quality salt to maintain mineral levels which may be depleted by skimming.

 

[zuzecawi]

Well, my garage has now had a shelf rededicated to my ghetto cuture station of rotifers and phyto. So far the only difference I can tell is that my tank is having a new bloom of diatoms. Which doesn't particularly bother me, I'm doing water change tonight anyways.