Best Metal Halide Bulb for SPS coloration

[Piper27]

Very nice! I think I remember your tank, it was inspiring and one reason I went and purchased the 10k xm bulbs.

 

[BrentH]

Anyone ever mess with the ushios 400 watt 20k?

 

[Jeremy B.]

Ushio 400w 20k has a slightly warmer appearance versus a Radium when being driven at lower wattages, such as using an electronic ballast at a regular 400w setting, or on a magnetic pulse start ballast. It does give of a very good amount of PAR off of those ballasts and settings for a blue lamp though. When upping the wattage through the lamp such as running it on a Super Lumens setting or an hold 400w HQI ballast it doesn't whiten up much, it still stays pretty blue, but the biggest thing is that you don't really see much PAR increase out of it like you would a Radium.

Really it all boils down to which ballast you're running it on, which setting if it's a select-a-watt, and what color you're after. All in all it's a good lamp, just still very hard to beat a Radium - other than spectral life.