How would this work

[BIG_Z]

Alright so I have two extra 75W HPS lights, I would like to use them to light two 40Gallon breeders setup as emersed. I know this light is not optimal for regular growth but would it still work?

[samamorgan]

High pressure sodium is red spectrum mostly IIRC. They would just give you nice short bushy growth, possibly with flowers (marijuana growers use them a lot for the final budding stage).

Plant's don't care what light you throw at them though, as long as it's in the right spectrum and there's enough for it. I'm not sure 1 75w HPS would be enough for an emersed 40b setup though, my only experience with those bulbs is the 1000 watt versions.