Peter and Shawn,
Did you guys already choose lighting for display tank?
If so, what brand and specification?
Too much text makes me dizzy.
Sorry.
Sorry to make you dizzy, but here comes more text
I really like the Orphek LED, but the clearance above the display tank is minimal, so LED was ruled out due to poor coverage. We were also looking for a quiet solution with no fans or overheating issues. LED meant 20-30 fans; as quiet as they may be, it all adds up.
We went with 12 x 250 watt double ended HQI MHL, with 12 x 39 watt actinic T5 . It is old technology, but it is proven. We are using three Aqua-Medic fixtures. One of the three fixtures has electronic ballasts and the output is 45% less than the magnetic ballasts, so we have new ones coming in.
We went with a mix of alternating 13,000K Aqualine Buschke and 14,000K Phoenix. The 13,000K is very white (I like it), and the 14,000K is eerie blue; together the mix is perfect. The 13,000K give us 350 PAR on the substrate, while the 14,000K give us 150 PAR. This makes our 250 watt bulbs equal to or brighter than many (14,000K - 22,000K) 400 watt bulbs. If we could fit more 410 - 460 nm blue light (in the form of LED) we would switch to all 13,000K MHL. I do however, like the shadowed mix of the two MHL. It breaks up the monotonous/homogenous (one colour) look of the tank when all the bulbs are the same. The tank has more depth with the mix and it subtly highlights certain coral groupings and rock themes. Most people wouldn't notice the lighting is different. We also like the following points about our MHL choice...
- more realistic, calm shimmer without funny colours (blue & yellow) of LED
- compact footprint (narrow fixture covers the whole 3' wide tank well
- PAR is basically the same (uniform) from centre of tank to outer edges
- only three clean fixtures needed
- absolutely no fans
- timer flexibility (9 light sequences) for sunrise & sunset (east to west MHL on/off sequence)
- actinic lighting for evening viewing, but we would like more
- although not proven to be beneficial, I like the idea of providing UV light, as the sun does (you can't fool nature

)
- manageable number of power source (ballast) boxes
- excellent clearance for tank maintenance. We never need to move it
- easy to install/mount
- small lens area to keep clean
- they get hot, but Peter's exhaust system acts as both a heat sink and exhaust fan
- it looks more like natural light than T5, LED, or plasma
- electrical consumption is about 20%-30% higher than LED but the initial savings (capital cost) is superior to the long term cost (operational cost). Most of the LED fixtures we looked at would take 10 years to pay off.
- the master Chingchai uses MHL
I like LED lighting and I'm working with the owner of Orphek LED to make them a more viable option for everyone. I definitely recommend LED for smaller tanks.
I have heard good things about the Neuco MHl bulb. We will be trying some soon. We are happy with what we have, but you of all people know what I'm talking about
http://coralvue.com/aquastar-14500k/ http://www.narva-neuco.de/