B13 : I always put cold water in my tanks. I have never had a problem.
A couple of mine:
Draining a tank and leaving the heater on. I started to fill it back up when i heard a crack. The next day, i look in the tank and the heater is filed with water and the tank is ice cold. I had to buy a new heater.
I moved some convict fry from one tank to another. The next night I use the same container for a water change and put water from the tap in there, I look down and see a dried up convict swimming around. I threw him back in the tank and he lived!
When I was around 10 or 11, I decided that I did not want to do w/c and I left the tank as is for 2 or 3 months. The nitrates were so high it killed some of my best fish.
I bought 2 oscars for a 55g, that had no lid. 2 days later i found them both dead, lying on the floor.
I once moved a tank out of a trunk and when I sat it down on the car, it's back cracked up. it could not longer hold water.
I once kept a pair on convicts in a 20g. i thought it'd be nice to add another pair. I threw them in and checked later, I found the new male swimming around, without any scales on him. He was a black convict, but his body was completely pink. He lived for 2 days in a community tank.
I am positive that there are many more, but at the moment that is all i can think of.
