Help!!

[jsodwi]

I think my tank is crashing. I set up a 300g a couple of months ago The fish I have I 've had for years. But this past few days I lost an oscar I thought he just got his ass kicked by the way he looked but then I got home last night and my Gar was dead too. They seemed to be in good health. My water levels are fine. My filtration is a bit small right now but I still have 3 power heads circulating water. The only thing I can think of is that i introduced a new fish a few weeks ago maybe he brought something into the tank but How would I know any help would be great.

 

[Caveman]

Did the dead fish have any noticeable defects? Do any of the remaining fish look sick or stressed? Keep a close eye on the recently added fish to see if he is acting strange in any way. Have the diets of the remaing fish changed recently? Any of the inhabitants laying on the bottom of the tank our appear to be gasping for a breath?

 

[rallysman]

what filtration do you have? maybe there is a lack of oxygen?

 

[jsodwi]

they all are eating good and swimming around. My shovelnose seems to be very active but not breathing heavy I only have one canister filter right now while i am in search of a wet dry but I have 3 powerheads at the surface so water isa moving

 

[Ash]

Is there anything that is noticeable on the actual fish its self? anything odd? or its all looks normal? do they have odd color poo??? (odd question but maybe its internal infection or something?

 

[DiXoN]

what were your water parameters when you checked them after the fish died

 

[managuense-fury]

might want to check the temp make sure its not to high or low.