I have had a watchman goby in my qt tank for about ten days now and he has been at therapeutic levels of copper safe for 5 days. Last night I noticed my ammonia alert badge was not it usual yellow color but slightly green, nothing on the chart but changing color so I decided to perform a 40% water change, got the water mixed and heated, added copper to properly level and performed water change, all was well the goby was a little freaked out but that is understandable. So I turned the light off and shut the door to my fish room. Later that night I checked on the fish like I always do before going to bed, the goby was nowhere to be found. Then I noticed I forgot to cover the small hole for the airline and heater cord. I looked everywhere in the room and finally found him on the other side of the room under the chair. I was heartbroken thinking of what I was going to tell my 6yr old daughter who named her Sandy. Then I saw her gills move. She was completely dry to the touch so I thought there was no way she would survive. I gently moved her back and forth through the water and about 10 mins later she swam out of my hand like nothing happened. I just checked on her after arriving home from work and she is doing great.