check this out. New Kessil A350 ( aka tuna blue)
I'm getting a pair of them as soon as released from J & L. Each light should be the equivalent of a 250-300 watt MH

Looked at the AI's and Radions but their mounting options leave a lot to be desired. The Kessils are mounted on a flexible gooseneck which attaches to the back of the tank. Also they are the only true led designed for aquariums. They make their own leds. It is one single led, not a bunch of little ones put together.

http://reefbuilders.com/2012/04/04/k...tuna-blue-led/

Well I've had my 5 AI Sols over my 240G and in a short period of time I've seen lots of grow in some zoas and other corals and the colors??? Spectacular!!!

The Kessil's are actually a bunch tiny little LED's clustered together much closer than those in a Radion or AI Sol. They just appear to be one LED, because they are that close together. Look at one close up and you'll see the smaller LEDS packing into the "bulb".

+1 to the above

I'm using three AI SOLs on my 120 and I like them a lot better than the 8 bulb T5HO fixture that I had. I am also using the baseline controller than AI sells. I have the whites at 45%, and the blues and royal blues at 75% and it looks a lot brighter than my old T5 fixture

Your 90 gallon should do just fine with two units and a controller

With a bunch of little leds you get better covverage as with one big one you get light emitted from a single point. My guess is some shadows.
If the sol and radion were not designed for the aquarium what were they designed for?

your right fishmanty . My bad. Here is their led technology. Jeff at J and L told me they were one giant led bulb, but on further research, they are lots of bunched up small led's. Point is that Kessil is an agricultural lighting company that has set it's sights on the aquarium industry, and they have designed their own led's just for us.

http://www.kessil.com/about/dense_matrix_led.php

Check out AI's website and you will see they use multi cree LEDs, each unit has eight clusters of three LEDs (one white, one blue and one royal blue). Could you be thinking of a different brand of fixture ?

http://www.aquaillumination.com/sol/

I can't comment on the mounting brackets as I mounted mine in a canopy

Sorry burgerchow, I did not notice your above post before I typed the one above.

My DIY LED's from Modular LED have a great shimmer, not as much washout from the LED's as the MH & I am getting much better growth on everything in my tank under the LED'S

there are some options out there to mount the AI & Radion out there, you just have to talk to the right people.