I replaced about half the water tonight with him in the tank. I unplugged the heater for a few hours and let the conditioned water sit next to the tank so they weren't the same temp, but were not to far off. However, I was told, that bottled spring water, like the kind that comes in a gallon jug, can go straight into the tank without being mixed with a conditioner. Is this true? Because if so, I think I am gonna start that. It just seems simpler. I always worry about using too little or too much conditioner. Anyone got any input or suggestions?