here it is

[reefburnaby]

Hi,

Typically (not all lamps and ballasts are the same...but usually for 5500K),

175W MH draws 2 amps and produces 12000 lumens (8000 lumens over 1000 hours).

250W MH draws 3 amps and produces 20000 lumens (13000 lumens over 1000 hours).

400W MH draws 4 amps and produces 33000 lumens (22000 lumens over 1000 hours).

So...you get about 60% more light with 250W over a 175W.

As for the 5500 lumen part...I think you refering to the colour of the lamps -- 5500 Kelvin. Higher Kelvin lamps have a higher proportion of blue light over red light.

- Victor.