What is the most energy efficient metal hilides?

[reefman]

Not talking about brand necessarily, more like single sided versus double. Electronic ballasts versus regular (Magnetic?). Does a EB really save you energy?

Stephen

[Kingfish]

On the one hand, the easy answer is to just say electronic ballasts are more energy efficient b/c they do use less power to fire the same bulb as a magnetic. Electronic ballasts ignite MH bulbs 100's of times per second while magnetic ballasts are on all of the time. The increments of time in between "pulses" saves energy and $$$.

On the other hand, magnetic HQI ballasts like the PFO use a similar igniter but put out more heat. Any time heat is produced, there is energy loss. The benefit of the PFO type magnetic ballasts is that they overdrive MH bulbs to produce more PAR (photosythetically active/available radiation). So the real question that you have to ask when choosing a ballast is, how much energy per PAR unit is used. Surely Sanjay Joshi has answered this question. Electronic ballasts are great b/c they are small and easy to mount. But if you really want to rock out an SPS tank, the single best ballast is the sunlight supply blue wave IV. It outputs 270w to drive a 250, or 430w to drive a 400w halide. I have seen a dual one of these running 2 x 400w coralvue reeflux 12K's and it ROCKS! It uses a bit more electricity, but who cares about a little electricity when you have a 5 or $10,000 reef tank with $1000's of dollars in corals?

[GMFett]

I have to agree with Kingfish. Its the Bluewave VII though.