That sucks dude!
I had one of my female employees do that at my store with all of our bettas. She used just the hot water. Not even any cold. I noticed the bettas all acting funny, so I went over to her bucket and put my finger in. It was so hot it hurt my finger. I looked at her dead in the face and said, "Seriously?..............." I just stood there and stared at her in Awe of the Stupidity. I then said, "Are you english............. or Retarded?"
She didn't make it very long needless to say...
I know it seems like I was harsh on her, but when I tell someone how to do something
and they decide not to do it that way and kill hundreds of animals in the process, I tend to get upset.