I got this fixture to replace an ATI 4-bulb Sunpower. I was running the Sunpower with (2) Blue Plus, Coral Plus and Actinic. I then added a Reef Brite XHO Actinic Blue to the front of the Sunpower. I really liked the addition of the XHO so I decided to add a second to the rear.
For my tank two XHO and four T5 would be too much light (roughly equivalent to seven T5) so I stopped running the two Blue Plus bulbs. The configuration was now (2) XHO, Coral Plus and Actinic. With the fixture mounted around 8" above the water I was able to achieve my PAR goal of 120-130 PAR on the sandbed.
The 4-bulb fixture and (2) XHO created a couple of "problems".
The first was to have an even spread into the tank from the T5's I wanted them to be the two center bulbs in the fixture. I fixed this by rewiring the ballasts so the center bulbs were a pair and the outer bulbs were a pair.
The second was the rear XHO hung too far back and around half the light was spilling out the back of the tank (see last photo). My tank is Waterbox 40.2 AIO, 18" wide display area. I tried angling the rear XHO forward for a time to make the 4-bulb fixture work, but this resulted in light shining into the eyes. The only solution I could see at this point was to just get the Reef Brite 2-bulb T5 fixture.
I have the fixture mounted 8" from the waterline and I'm seeing PAR in the 130 range. I was a little concerned with what the aesthetics of fixture may be since I couldn't find any photos of one installed, but I think it looks just fine. When looking straight on you don't even see the T5's.
4-Bulb ATI with Two XHO
