[bauder1986]

Keep this in mind to as well when you are calculating the amp of your fixtures that they draw. 110 watts of lighting is 1 amp. soo a 250 watt MH is 2.3 amps of steady draw and then you have to keep in mind how much draw your ballasts have when the fire up.

Now keep in mind that when electricians wire in a house they run a parralel that runs no more that 12 amps max! Every plug in a parallel is concidered one amp and every light is concidered 1 amp and smoke detectors are concidered .25 amps. Pot lights are concidered .5 amps since most of them are 50 to 75 watts max. but the moral of the story is that your tanks is most likely not the only thing that you have plugged into that parallel so you may have more draw than your tank such as your TV which probably draws around 3 amps steady. and your lights draw 8.2 amps steady...so yah that is pushing it.

But yah i would replace the old 15 amp breaker with a new one just to be safe and run a dedicated GFCI 20 amp breaker to the tank with 12/2 wire and leave it at that.