Brownstone, the trout tank is part of a tank system I maintain for research purposes. It holds about 400L of water and has a partial flow-through coming via a dechlorinator. The bulk of the water is recirculated through a big gravel filter.
Weedy, all I can say is that I am more surprised than you. I have had these trout for about 3 years. Usually they just try and wack my arm with their tails as a defense behavior. When this one bite me today I was just laughing with astonishment.
Good thing they aren't Bulls. I might not have made it out alive!