i think the question was what is too much light? i've used 6-1000 watt hps lamps over a 4x8 before in a SOG grow before and had really good results. No staging, just straight 12/12 18,000 lumens per square foot. But you have to remeber plants can only use as much light as they have available co2, they can only use as much co2 as they have nutrient, they can only use as much nutrient as the root have available air etc. everything needs to be in proportion, you can raise one w/o raising the rest to achieve the best results.