What are the differences between a 150, 175 and 250 as far as the amount of light and heat they produce? (no chiller) What is the difference in the double ended and single ended halide bulbs? and Which one would be right for my tank? I was looking at few options. The fixture is nice and clean but limits light and the reflects are not the best quality. The retro on the other hand is a better deal but i don't know how to install a retro kit. I build computers for a living so i think i can do this First one is 48 inch Current USA SunPod 2x150W 14K HQI-MH w/ 18 Lunar Lights Price: $510.00 comes with 2x150 Bulbs Price: $710.00 comes with 2x250 Bulbs Description The Current USA SunPod produces an enormous amount of light and cuts through water to even the deepest depths. The PowerPaq 14,000K HQI metal halide(s) produce the energy your corals will need while also providing the natural shimmering effect found on coral reefs. Powered by our proprietary microprocessor based electronic driving system, the high-intensity blue light produced by the 14,000K PowerPaq HQI is so brilliant—no other supplemental actinic lamps are required. Dimensions: 8.25"W x 4.5"H Power features—Housed in a sleek aluminum enclosure, the SunPod features an integrated quiet cooling fan and strategically placed side vents, making for a really cool fixture. Hammertone HQI reflector pumps up the light output—all being protected with a sealed glass lens. Plug-and-Play mounting features allow the SunPod to be used on any tank! Panelit—feature both Blue and White Lunar Lights mounted on a removable LED panel. Each color is independently controlled, allowing you to use both colors for a gradual ramp up, or one color for nocturnal viewing. Specifications Model: 1164 Length: 48" 14000K PowerPaq: 2 x 150W Lunar Light Blue/White: 9/9 Hanging Kit: No Automatic Timer: Yes Dimensions: 48" x 8.25" x 4.5" Total Watts: 300 Total Amps: 2.6 Fixture Configuration: C Option 2 Metal Halide Retrofit Kit w/ 2x175W 14000K Ushio Price: $460.00 comes with 2x175 Bulbs Manufacturer: IceCap Dimensions: 2 - 13.0" x 9.5" x 4.5" (L x W x H) Retrofit metal halide lighting system complete with two Sunlight Supply Reef Optix 2 Retrofit Reflectors, two IceCap Electronic MH Ballasts: 1-175W, two Ushio 175W 14000K Metal Halide Bulbs, two Sunlight Supply Female Receptacles, and two grounded power-cords. Option 3 & 4 Metal Halide Deluxe System w/ 2x175W 14000K Ushio Blst- $549.00 Metal Halide Deluxe System w/ 2x250W 14000K Ushio Blst - $589.00 Manufacturer: IceCap Dimensions: 2 - 15.0" x 9.75" x 4.5" (L x W x H) Metal halide lighting system complete with two Sunlight Supply Reef Optix 1 Plus Horizontal Reflectors, two IceCap Electronic MH Ballasts: 1-175W, two Ushio 175W 14000K Metal Halide Bulbs, two Sunlight Supply Female Receptacles, and two grounded power-cords.