lol. sorry I should have metioned that. I'm looking to spend about $400 bucks. It seems that dimmers are only needed with acclimation of corals to the tank as to not shock them but, I've read its not neccessary considering the standard Apollo SolarBlast you can turn off a set of lights to help with acclimation.
As for the Apollo Solar blast using a single fixture?
To Dim Or Not To Dim?
Well if you're already set on this vendor (not familiar with them)
and have any plans for a controller, then from Apollo Reef's website it looks like
their $399 unit is dimmable. For the small difference in cost from
the $359 Ultra model, I'd probably consider getting the dimming feature. Having a controller is mandatory, however. I personally consider dimming a "fiddly extra" on a good, correctly sized fixture but know other smart people who feel otherwise. YMMV? :wink:
If you were happy with your halide's look and feel - outside of thermal factors - then my prediction is that you will feel at home with the Apollo and won't miss dimming. Just be aware that (with almost all LED's) PAR:visible light tends to be a lot higher than with halide, so even if it doesn't look quite as bright as you remember it, it still is very bright like a fresh bulb change to the photosynthetic organisms in the tank. :neutral:
What If You Only Get One?
My prediction for coverage (from their claims) is that you have plenty of light all the way to the sand bed for SPS with this, but the wings of your tank will be a bit dark. Again if you are inclined toward this particular lighting unit, I think I'd roll with a single unit as you plan and just enjoy the different lighting zones - make the most of them. Make a smaller rock mound/column/bommie or atol in the center under the bright light - the shading could add drama to a setup like this. I would also plan to use a flexible hanging/mounting system that will let you vary the height as needed for viewing and maintenance. Being able to easily raise and lower the lights will solve your acclimation issue as well. A pair of
Sunlifts make a nice solution, but even
standard 1.5" lamp-chain is a nice and user-friendly solution.
Expense? Yeah, more DIY suggestions. 
Just to throw it out there since expense was a mentioned factor and your tank isn't really that deep, I'll try to compel you with price and an alternate path. :angel: My 30 bulb GU10 fixture ran me well-less than $200 to cover my 50 breeder (36x18x18), including 10 spare bulbs. It's DIY, but a bit simpler, or less mysterious (to me anyway) to put together than the "from-scratch" DIY builds that you see most everywhere.
It amounts to screwing twist-in bulbs like these...
... into sockets like these...
... which are screwed to an appropriately shaped-like-your-tank-top, solid surface (tempered masonite, acrylic or something more creative but similar) and it is wired as you would wire common household wiring - so a bit more familiar to most people. You might even consider two small installations of GU10's to fill in the "dark wings" of your bow-front if you go with the Apollo.
A little
searching should reveal lots of prior art to give you an idea whether GU10's would be more interesting than other DIY avenues.
One thing you'll get with a DIY - whether GU10 or otherwise - is the perfect coverage for your "oddball" tank.
Good luck with whatever option you pick!! :bigsmile:
-Matt
