Question about overloading your electrical breakers?

Im running a 400watt digital ballast grow light with an air pump and fan. Every now and again the breaker will pop and shut off everything in my bedroom where my setup is. My question, what can i do to make my bedroom able to handle more electricity? I dont want to worry about the breakers all the time. Ive had this setup for a few months in this bedroom and havent had a problem until now?

What else is on the same circuit?

Flip off breaker and check adjoining room receptacles to determine if they are on the same breaker.

Since the problem is new it seems like a space heater or something was plugged into another room but is on the grow circuit.

You really only have two options: Lessen the load on the current circuit or add an additional circuit. I suppose you could use an extension cord but they often present a trip hazard and are only meant for temporary use.

edit: another thought on why it is a new problem.. it could also be a sign that the breaker is on it's way out. Worn out contacts will lead to arcing, which will trip it. I've had my main breaker do this to me.