Originally Posted by Chlorophile
As a refresher, I have two Exo Terra tanks: one 36x18x24, the other 24x18x36. Neither will house animals - only plants. Both are intended to be set up in a living space on stands (or suitable furniture) so they can best be viewed with regularity, rather than in another room where suitable industrial shelving already exists. The long tank was originally going to be under a suspended unit of 4 or 6 T5HO lights, but given its new display location and the fact that it won't be on a shelving rack any more, I switched it over to a hood instead. I got the large Exo Terra Compact hood (with the four sockets) that I am going to use Jungle Dawn 13W fixtures in. I went with this based on the advice of the vendor I used. Upon testing it atop the tank, the light is sufficient but not as bright and all-illuminating as I was imagining it would be. If I situate the hood over the rear half of the tank top, the front is dimmer than I would like; and, as you'd expect, when I move it to the front the top of the rear wall is dim. Putting the hood in the middle creates dim spots on prime wood mounting spots due to the tank screen top's center brace, so I'm wondering what to do. I don't want to overkill it with too much light, but when I tested adding one of my other, smaller hoods with three 9W Jungle Dawns in it (to the front, with the long hood in the back), it is much more to my liking.
Well, you could use those two two banks of Jungle Dawns if that is "to your liking". Nothing wrong with that, and you already own all that equipment.
An upgrade (in terms of intensity as well as quality of light) would be Spectral Designs panels. These can be built (they're all custom built, so email SD and ask Kurt to price out whatever it is you want) with added LED spotlights (up to 50w spots, and dimmable too) so punching light down to the bottom won't be an issue. The spots can be located so that they won't interfere with your 'wood mounting spots', too.
You can eliminate the center bar issue by removing the stock screen top, installing a piece of glass the leaves a couple inch strip open in the back, and making a screen to fit that ventilation strip. This sort of screen kit works great:
I think kimcmich has a big viv that is lit with metal halides...I'll try to find the thread.