All Fish Go To Heaven

[term_22000]

So pretty much all my fish went belly up and I'm curious why. I've had my tank cycled and all my fish were doing well until I put some algae killer in that I've used before to kill the excessive amount of algae that has seem to explode in my tank all of a sudden. Any ideas as to why this algae killer killed all but my two angles?
Thanks

 

[Baccus]

Possibly reduced the oxygen to such an extent that the other fish pretty much sufficated, much the same way as natural fish kills occur in the wild. Or the algea killer may have had a clumping quality which effectively clogged up the fishes gills.

 

[HayzH]

how was your filter cycled?

 

[BigbruiserAl]

Did you read the label and see what dose to add? did you missread it and over dose?