I did some energy calculations and then some cost different for the initial purchase and decided to get these lights instead of LED's, perhaps later, the LED will surpass T5's but these are really a winning fixture. Warning, they are not cheap.
I am using some on my 70 Gal manzigumi.
It took me awhile to figure the controller, but once I did and got that dialed in good and the bulbs burned in for about 50 hours, this light works like no other I've had. I also did some measurements vs the Tek, and it's basically 25-50% more light. I confirmed it with the PAR meter.
Usually I am highly skeptical of such marketing talk, and rightly so, I will say it's correct in this case.
So why was I really interested in this fixture?
1. Reef folks have been hounding me.
2. Is the light that much higher vs the other decent T5 brands?
3. The dimming option.
The dimming option is really cool and ends up costing you much less and is far more natural and you can vary things around a great deal. It has 2 channels, so say you just want 2 or 4 bulbs on initially, and have then come on at say 8 am and then run up to say 50% power at 10am, then from 10am till say 12, have the other bank of 2 or 4 come on and run up from 0-50% in the next 2 hours, then all the lights from 12-2 pm from 50-100%, then from 2 to 4- back down to 50%, and then 4-6pm, down to 0%.
You can split the channels up anyway you chose, but by using only low dimmed light the first and last parts of the light cycle, you can crank up the middle portion, but also still have plenty of time before/after work to see the tank.
I use about 20% less energy using this fixture than the LED option with similar PAR over 10 hours. Peak lighting is about 100 umol higher also.