Dwarf Gourami dead after water change

[JPerez57]

Hey guys I just started by first aquarium and it's about 3 months old now.

Today I changed the water on my tank today and immediately after my Gourami sank to the bottom and stayed there until I left to work. I had tried to feed him but he didn't bother moving from his spot. When I can home from work maybe 10 hours later he was dead.

He was fine before the water change and all the other fish seems perfectly fine now. I feel awful because I feel like I somehow killed him by changing the water.

He does have a small white spot instead of orange on his side but I'm not sure if that means he was sick or what it is.

Can anyone give me an idea as to why hes dead and if it was because of my water change what can I do differently? I had done a few changes before without any problems.

Thank you!

 

[NatureGirl]

So sorry for your loss, JP! The only thing I can think of that could have killed your fish from a water change is if you filled the tank with untreated tap water. But if that were the case, it probably should have affected all the fish. So that's unlikely... Maybe while new water was being added to the tank the fish got caught in the current and was pushed into something hard?