I am about to give up...

Ok - so I successfully cycled my tank, and got new fish. This was 11 days
ago. Well - I got home from work yesterday, and all but one of my fish were
dead. They were all fine before I went to work (my angel is the only one
left alive). They have been seemingly ok for the last 11 days.

My ammonia did a mini spike up to 2, but I have managed that with water
changes and ammo lock. It was only one day....

What in the world happened??? What could it have been that 3 corys, 2
swords, 2 gourami, and a rubbermouthed pleco all died at the same time, with
no warnings signs...

My ammonia was 0 - .25 when I found them dead.

Thanks,
Connie