So my friend is out of things to do. He can not figure out what is wrong with his clams, so I took some pics and am hopeing you guys can help me out. His lighting is 150W MH and 2x24W t-5 It's a 30G Finnex Tank. At the time the photo was taken all the parameters were within spec. That includes alkalinity, calc etc... this is the bigger of the two clams and the first to go brown, now the little guy is going brown. They still open and close like normal, so I'm not sure what is going on please let me know what is wrong.