Tiger barbs

[hanziie]

So ive just come back from a 10 day holiday from america and my brother has been looking after my fish.
When i got home i noticed that the filter was about to give up on life so i went and got a new filter asap and put it in last night i got the fluval u2, noticed this morning that one of the barbs was litrally dead i went out and for a few hours came back and all my barbs are dead!

Could it have been the filter?

 

[Toad]

What was wrong with the original filter, and did you put the old filter media in the new filter?

 

[hanziie]

The old one just stopped working it was pretty old and the 2 filter were of different make the orginal one was just a sponge as the new one had sponges and media in it