My Gourami Is Unwell! Please Help!

[JPR]

Hello,

My Honey Gourami is lying all day at the bottom of his tank, still breathing, and once in a while he will struggle to the surface to grab air. He is by himself in the tank (5 gal), the tank is filtered, the temperature is normal, the nitrates are at 0, and I have remedied the ammonia with API Ammo Lock. The tank has been set up for 2 months, and he has been fine until a couple of days ago. Today I added an airstone and a live plant. Yesterday he ate some flakes, but he is worse today than yesterday. I also already tried a partial water change and made sure to condition the new water. He has no fungus or parasites. What else could be wrong with him? Please help!

Thanks,
J.P.

 

[NickAu]

 
I have remedied the ammonia with API Ammo Lock.

The only way to remedy ammonia is with water changes. How high was the ammonia? Your fish most likely has ammonia poisoning.
 

 
I also already tried a partial water change and made sure to condition the new water.

I would change at least 50% of the water now.

 

[Jeremy180]

Please change as much of the water as you can without beaching your gourami, as soon as possible.
While API ammo-lock does change ammonia to a less toxic form, that form is still prettyHarmful.
 
(Don't forget to unplug the heater first, or it may well explode)
 
EDIT: You didn't mention your nitrites, I've looked up how Nitrites poison fish and it seems to act on them like carbon monoxide does on people.