I run 3 x 15 amp breakers(300 gal with 125 sump) and I was told by my electrician that 1x 15 amp breaker could handle a good 3000 watts of power I use the 3 I do have power bars of course but I also spread the load between the 3.I do have a controller with the power bar and I have lights and pumps plugged into it but I have left room in case I decide to expand on that.I have 2 dart pumps,1 dart skimmer,2 heaters 250 and 300 watt and I need another.My sump is in the garage and the garage is cold so the heaters run often,1000 watts of lights.I have 2 power heads in my sump.I also run a kalk reactor and 3 aqua medic doser pumps but they don't run often.