HQI vs. Mogul

[PowerManJ316]

mojo,
Your results are correct and they are completely in accordance with what I posted. However, you have one small error. The Icecap is not limiting so to speak the power to the bulbs. It is a 250W ballast powering 250W bulbs. Thus, it is running exactly as intended.
The M80 250W ballast is overdriving the bulbs because they are 250W bulbs that are running at 310W - thus being overdriven.
I agree that certain bulbs will produce more PAR regardless of ballast. However, a ballast driving a bulb at 310W vs. 250W should ALWAYS produce more PAR regardless of type.
The intensity difference between an HQI and a Mogul bulb is not necessarily from the position of the bulb in the luminaire. Again, any bulb being driven at 310W is going to produce more PAR than the same bulb being driven at 250W. Thus if you hook both a single ended mogul and a double ended HQI bulb to the icecap ballast, the PAR will be similar because both bulbs will be driven at 250W.
You simply cannot compare an HQI setup and a Mogul w/electronic ballast setup because there are multiple variables not being accounted for - the main one is the true wattage the ballasts are running at.
In conclusion - estimate how much PAR you need and find a combination of HQI or Mogul with an appropriate ballast (electronic/magnetic).
HTH,
Jeff

[Schwaggs]

I think the point Mojo was trying to make with the reflector is HQI reflectors achieve high PAR readings by being configured like a spot lights while most SE reflectors act like flood lights. Take a 250W Pheonix 14K DE and SE bulb driven by an Icecap ballast. Both bulbs will draw close to 250W in this configuration. The typical HQI reflector/UV shield combination will yield higher maximum par than the SE config. HOWEVER, the total AREA (square inches) covered at this maximum par is small. In other words, the HQI cinfiguration ends up acting more like a spot light while the SE config acts more like a flood light. Both have applications to which they are better suited, just make sure you choose the right one for your system. HQI and more importantly, most HQI reflectors, work well for deep tanks or where the most extreme par is required while SE typically works well for standard depth systems.

Take a look at Sanjay's reflector analysis articles for more info... http://www.reeflightinginfo.arvixe.com/articles.htm