why are all the fish at the top of the tank?

[lowlandgorilla]

My brother no longer looks after his fish, and I have taken over, with little knowledge about tropical fish. At the moment they are all at the top of the tank, and have been for a couple of days. Could this be eating the stuff that came out of the filter (I obviously didn't clean it as well as i thought), is this ok? or could this be some other reason, such as lack of oxgen. Please help.

 

[wuvmybetta]

Are they mouthing at the surface in a gasping fashion? This is a definite sign that something is not right. Take a water sample to a shop and have them test your water. For now a water change couldn't hurt. Also make sure they have lots of surface disturbance for increased oxygen.

 

[clutterydrawer]

What kinds of fish and how many? Do you know your levels of ammonia, nitrite and nitrAte? Do they look like they're actually ill? How big's the tank?

 

[nightlife20]

before doin a water change... do u know what dechlorinator is?

and also how to use it?

 

[FrankSlapperinni]

My brother no longer looks after his fish, and I have taken over, with little knowledge about tropical fish. At the moment they are all at the top of the tank, and have been for a couple of days. Could this be eating the stuff that came out of the filter (I obviously didn't clean it as well as i thought), is this ok? or could this be some other reason, such as lack of oxgen. Please help.

If you cleaned the filter, you may have killed all of the beneficial bacteria living in it, and thus allowed toxin levels to rise in your tank. take your water to the LFS and have them test it. while your there, you may want to buy test stripes of your own. Make sure to buy them for Ammonia, NitrAte, and NitrIte.
If you want to understand more about your aquarium, you should read the pinned topic in the beginner section.

 

[ger87410]

Luckily cleaning out the filter won't kill all the bacteria, just a fair share of it. U should still have enough left to where you won't have too many problems I think. Atleast I know you won't have to recycle. If you want to clean out your filter the right way, do it in some old tank water. Then you won't kill any bacteria.