well guys i hope you all have some advice i have had this deruasa for about 6 months now it have white stridation marks all over it's skin. and now about 3 weeks after that it is acting funny like it might die. now i did just have a crosea die but i do not know why my water is perfect except my Kh is 15 and i like it at 14. and it just up and died over night. now i also just bought a squmosa that is beautiful. now the only thing i think it could be is my amount of light. first off i have a 80 gal and the water is about 2 feet deep. i have 3 175mh bulbs ( 1 20K and 2 6500K) and a 96W actinic PC light strip. do you all think i have enough light to sustain my clams in the sand bed as that is where they are. i am about to purchase 330W more of VHO's next week and build a new hood for it. and i am sure that will help. well i hope you all have some advice about my situation as i do not know much about calms but only recently started haveing problems with them. thanks for the help in advance. bye