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55g - Adding Metal Halides

  • 55g_with_new_canopy

Early in 2003, I bought a virtually new MH setup from a member of The only thing I was lacking were the quick disconnect cords that run from the mogul sockets to the ballast, but another person pointed me to $18 later, I was finally in a position to fire them up! This is a PFO Dual 175w system, which I feel is plenty for a 55 gallon tank. The aquarium is narrow, and not very deep. Using Ushio 10,000K mogul-based MH bulbs, the tank still needed actinic supplementation.

I'm using two Uri Super Actinic 110w VHO bulbs, which run parallel and sandwich the 2 MH bulbs. The reflector is the original 48" flat panel my VHOs used.

I added 'legs' to each end of the canopy to lift it up off the tank and away from the water.


No sealer was used, as I wanted to see how this would work out aesthetically as well as heat-wise.


Looking up into the opening, you can see the unlit MH bulbs and one of the reflected actinic VHOs.


With only Actinic bulbs on, the tank has a surreal look to it as various corals glow.


Actinics on, and the right MH bulb. SUNRISE!


All lights on, with a total of  570w of lighting.


The right MH off, the left MH on plus actinics. SUNSET!

Factoid:  The MH bulbs are 9" off the surface of the water.

Because a conversion to a new lighting system can affect a tank adversely, it is important to acclimate the corals to the newer (brighter) light. For the first few days, I ran the actinics all day long, matching my previous schedule, but only had the MH on for 4 hours. Every two days, I increased the MH lighting period by 1 hour. After two weeks, my lights are on the full schedule and nothing has reacted badly. Quite the opposite, the corals seem very happy to bathe in the 570 watts of light. And the ripples across the reef look great!

I added a piece of black acrylic across the front opening to see how that would look, plus to gauge any heat issues. With it in place, the tank hits 80.7°F during the hottest part of the day. I'll build a new canopy in the near future, and my goal is to use the black acrylic as a sliding panel that can be raised up and out of the way. I may add a couple of fans to vent the canopy area as well.

Lighting Schedule On Off
VHO Super Actinics 10:00 am 9:30 pm
Right MH 10,000K 10:30 am 8:30 pm
Left MH 10,000K 11:00 am 9:00 pm
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