Help! Fish Dying!

[selena14]

I just got 3 fish this week. They were all fine the first day, but one of them couldn't swim and has now died, of the two remaining one seems healthy and the other is laying at the top of the tank on its side and cant swim. Could you please tell me what is wrong and how could i help the tank? I put the sick fish in a separate tank with new clean water. 

 

[the_lock_man]

Hi Selena, and welcome to the forum.
 
Can you answer a few questions for me please, as there isn't a lot to go on in your original post.
 
How old is the tank?
How did you cycle the filter in the tank?
What are the current water stats, for ammonia, nitrite, nitrate, pH?
What are the other inhabitants of the tank?

 

[Lunar Jetman]

Also, what size is the tank?

 

[tunagirll]

Also, did you condition the water before putting the fish in? (that is, use water conditioner in the water to remove chlorine)

 

[fishy_wishy]

Also what kind of fish are they?