I want to run 2 -400 watt hps and a 6 inch fan and a air pump and 150 watt fluorescent light in my grow room and my house has a 100 amp fuse panel. Should I add a bigger breaker panel or is my 100 amp fuse box enough to power the room without overloading it?????
Don't worry about the overall capacity of the panel but of the circuit you will want to run your grow op on. You've listed about 950 watts of draw plus the fans and air pump, so call it 1200 total watts. On a 120/110v system (standard in the USA) that could be handled on a 12-amp circuit or higher.