Fish dying

[Pareeeee]

You can't really tell what's wrong with a dead fish. Their body colour changes after death and other fish start nibbling at their body.

I'd say your loach is probably being aggressive at night when you don't see him. I suggest finding a new home for him. They get huge, and certainly should never be kept in a 10 gallon tank.

Did you replace ALL the filter media at the same time? If so, that would have caused a bacteria inbalance. Only replace some of the media at a time, not all, and make sure you don't clean the aquarium in the same week you clean the filter.


...and just in case you took the other person seriously...no, otocinclus are not aggressive. They are the opposite of aggressive :P

I wouldn't feed bloodworms or brine shrimp as a staple. Get a good tropical fish food and feed the bloodworms only as treats.

Can you take a look at your living fish and see if there are any abnormalities? Clamped fins, white tufts or spots on body, cloudy eyes, pale band through the middle of their body, ragged fins, red gills, etc?