Some time ago my wife started leaving the lights off on her tank (probably about 3-4 months ago). now when we turn them on to the normal lighting setting the hang out at the bottom of the tank and stop moving. I think they just got too accustomed to the dark. I am now leaving the lights on in the lowest setting and in another week or two I will start cycling the full power lights on in 15-30 minute intervals and lengthen the duration every 2-3 days. What are your thoughts on this? Oh by the way there are 3 goldfish in a 40 breeder.