its a kind of metal halides,
Well, there are a lot of schools of thought on the relative merits of each bulb. HQI bulbs require electronic ballasts, pendants with glass lenses (as these bulbs are not UV shielded, like mogul or medium base variety bulbs). I have read a number of studies that imply that a 150w HQI in a well-designed pendant (I use and really like the ReefOptix 3 by Sunlight Supply), can yield a higher PAR value than some 400w medium base bulbs...The implication here is that if you combine a good ballast, a fine pendant, and a quality bulb (such as the Aqualine 10000k or Ushio), you can have the PAR value of a higher wattage bulb, with greater electrical efficiency. On the down side, it seems like there are fewer bulb choices of bulbs in the HQI format, as compared to medium or mogul base bulbs-but this is changing all the time!>
thats from Scott F. at wetwebmedia, they are much more educated than me hope it helps
Well, there are a lot of schools of thought on the relative merits of each bulb. HQI bulbs require electronic ballasts, pendants with glass lenses (as these bulbs are not UV shielded, like mogul or medium base variety bulbs). I have read a number of studies that imply that a 150w HQI in a well-designed pendant (I use and really like the ReefOptix 3 by Sunlight Supply), can yield a higher PAR value than some 400w medium base bulbs...The implication here is that if you combine a good ballast, a fine pendant, and a quality bulb (such as the Aqualine 10000k or Ushio), you can have the PAR value of a higher wattage bulb, with greater electrical efficiency. On the down side, it seems like there are fewer bulb choices of bulbs in the HQI format, as compared to medium or mogul base bulbs-but this is changing all the time!>
thats from Scott F. at wetwebmedia, they are much more educated than me hope it helps