Random deaths...worried!

[farli]

I have a 20 gal live bearer tank...and i have some just randomly die...i know they all eat...i make sure...but they just die...no diseases...i watch very carefully...i don't have a water tester...tank is established for over 2 yrs...some fish i have for a while...any questions or comments please post!

 

[ChilDawg]

What does "a while" mean? I know that some livebearers have short lifespans...

The other thought is that if they are guppies or mollies, they might need some salt or else they'll succumb to fin rot and the like...mollies also need greenery to survive.

 

[Matak]

Yes and is it the fry that die or the parents? Could you please give us some more info on your tank. Things like how big, how many fish, how often you do water changes etc.