Metal Halide - Choices

[fkshiu]

Joe, it depends on what you want your tank to be. I get fine coverage and grow all sorts of high light stuff with 2x175W Vertex electronics running Iwasaki 15Ks under Lumenmax pendants. PPFD per watt, this is the most efficient set up according to Sanjay's figures using less electricity than 150W HQI system but putting out more PAR than some 250W systems:

http://www.canreef.com/vbulletin/showthread.php?t=59449

Understand that I have a mixed reef with lower light creatures too and my tank is on the shallow side for a 6-footer. Looks wise no one has ever noticed any dim spots. If you want a full out SPS garden, however, going with three 250W pendants is the better choice. You start getting diminshing rates of return once you hit 400W territory.

You can have a closer look when you come by for you macro later this week.

[Myka]

Those Iwasaki bulbs on electronic ballasts are a PAR breaker...not typical! You can't get the same PAR using different bulbs on that ballast. As long as someone is happy to commit to that one single bulb, that's a great choice! Pricey bulb though...

[lastlight]

That sums up my radium conundrum. You sorta gotta commit to run them proper. Unlike that 175w choice tho you're not quite as ltd as you will get awesome par out of a ton of 250w bulbs tho you may burn them out prematurely (unlike with the radium).