Fixing the fish tank

This week I was talking with my manager when all of the sudden I realized water was running somewhere around the corner. The only thing back there is a fish tank. I rushed around the corner to find that a resident had opened the doors of the cabinet, was holding a little tube and was "fixing" it. Water was pouring out from somewhere. 

There was a red shut off valve so I shut that, which didn't seem to help. When I called the emergency fish tank man, he told me to "Never, ever shut that." Apparently it causes the tank to overflow. Oops. I quickly ran over and opened it all the way as he instructed. The floor is carpeted so I'm not sure how much water gushed out before the valve was opened back up. The fish-tank-man came out and fixed it all. When I left there were still some bath blankets there soaking up the excess fish water.