120w enough to make a single trained plant bloom well?

Yes if it's a true 120 watt from the wall , rule of thumb is 100watt per plant is enough to bloom ... thoe ppdf counts here you can get simple PAR apps for your phone with accaute results your looking for a good distance not to burn your.leaves even leds need 24inch clear if strong and also you want about 700 to 900 micro moles m/mols per square meter per sec ... hope this helps