# 2 HQI over 6 ft tank



## niko (Jan 28, 2004)

I have a 6 x 2 x 2 ft. Oceanic tank that has a 1' brace in the middle. The tank is lit with 640 watt of VHO lights. The bulbs are mounted in two 72" long white Hamilton reflectors. 

When I measure the light in the middle/bottom of the tank with my camera the exposure is the same as in my 30 gal. 2' cube with one 36 watt light on top. So I consider MH lights or T5s.

I consider buying two 150 or 175 watt Double Ended MH pendants to replace the VHO lights. 300 watts of HQI light may not sound enough but maybe it is?

The alternative is the T5 fluorescents but I surely have to have at least 600 watts of them to see a difference. Also I'm not convinced that they will penetrate the 2 ft of water as well as the MH.

Any opinions on the choice T5/HQI? The number of HQI pendants? Light penetration? Placing above the tank?

--Nikolay


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## gnatster (Mar 6, 2004)

The HQI MH Bulbs may not give you the coverage you need for the length of the tank. It is generally considered that they will cover a 2ft sq area comfortably. Ideally 3 150W bulbs would cover the tank fully, however one would be centered over the center brace I think, diminishing it's effects. 

I have seen a 215, a deeper 6' tank successfully lit with 2x150W mogul base bulbs. I believe the trick is the height the bulbs are mounted above the tank. These are fairly high, about 1.5-2ft above the tank allowing for a wider coverage area. Light spillover into the room could be an issue at this height.


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## Mjproost (Nov 17, 2005)

Also, the efficency/shape of the reflector will play a big role it lighting that much space. 

If you want MH I would stick with Mogul base. That way you do not need a glass cover for the light which would block a portion of the light intensity. 

Sorry, I do not know anything about the T5 options to offer an opinion.


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## bharada (Apr 17, 2004)

Niko,
I have a 120g (48x24x24) lit with a 4x54w T5 Tek Light fixture (2 6500K GE Starcoat + 2 6000K Giessemann daylight). I run two bulbs for 12 hours and all four for only 4 hours mid-day. It's enough light to keep the tenellus you sent me purple.


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## dennis (Mar 1, 2004)

T5 seems like a good option to me. I just switched a 3x36 PC to 2x39T5 and the growth is noticably improved in only a week. I am not using polished reflectors either, just sections of white 4" PVC

Is your middle brace clear? Personally I woudl say go with 6x39watt or 8x39watt T5. If you find a good source for the ballasts (I found the Advance brand (made for T5) on ebay for 13$ and free shipping) each ballast will power up to 2 54watt linear T5 or PC. I used the cheap $2 a pair endcaps and GE starcoats all from www.reefgeek.com My 2x39watt retro cost me ~$50 with bulbs, wire, endcaps, PVC reflectors, ballast, etc.


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