Dead Rummy Shoal

[GeoffLondon]

Oh dear, I've just found that my entire rummy nosed tetra shoal is belly up! I have no idea what caused it....they are in a tank along with 3 platy's, 3 angelfish and 2 cory's and the whole lot have been fine for nearly 6wks (when I bought the fish apart from the one poor rummy that had been alone in the tank for months!) but now all 5 rummy's are dead

Has anyone got any idea's on what could have caused this...and only these fish to die? I have my tank on a light cycle with 2hrs off every 5hours and I have noticed that when the light comes back on the Rummy's were the last to "activate" again. They would often lie very close to the bottom and take quite a while to regain their pigment....could this light cycle be the cause?

 

[snowyangel]

Are you trying to keep aglae down is that why you have this light timer? I generally keep my lights on for 8-10hrs a day then they get shut off for the rest of the night. The lights may startle them but i dont think it would've killed them unless for some reason it put them into shock but i've never heard of lights doing that.
Did you notice any fin, scale, or gill damage? Like ratty fins, redness to the gills? When was the last time you did a water test for ammonia and nitrites?