# Metal Halides



## Mark Evans (28 Dec 2008)

ok, im in the market for some new lighting. now im wondering if someone can help me out. i dont know if to go with leds...

http://www.aquaessentials.co.uk/index.p ... ts_id=2238

or halides with t5s, probably this option

http://www.aquaessentials.co.uk/index.p ... ts_id=1093

why do systems that are metal halide also have t5 tubes in them? whats the benefit of t5 and halide lamps? obviously theres more than enough light and i would only run whats required.


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## Luketendo (29 Dec 2008)

*Re: mteal halides*

The T5s are there mainly for Actinics which are used on reef aquariums to supplement the light coming from the halide.


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## George Farmer (29 Dec 2008)

*Re: mteal halides*

The Easy Life units look great but at that price I'd consider 2 x ADA Solar I NA 150w or even the Grand Solar.

LEDs are a lot cheaper to run, run cooler and are waterproof.  It takes a while to get used to the light they give, compared with fluorescent, as there's several point sources.  These give a pleasing ripple effect that only used to be gained by metal halide.  I'm not sure how using T5 with LED, like the Easy Life units, would compromise this nice ripple effect.

T5 and halide combos are ideal for staggered photoperiods with a midday burst of light i.e. use the T5 for the entire photoperiod, with a few hours of MH during the middle of the photoperiod.

Also consider the Giesemann Infinity units MH and T5 units - http://www.giesemann.co.uk/infinity.htm

If you only want to run the light required then 2 x T5 is plenty for most set ups.  Halide is an expensive luxury (both outlay and running cost) but as you've seen at TGM - it's very nice...


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## fishgeek (29 Dec 2008)

can anyone explain why aquarium units are so expensive

HQI bulb so good quality colour rendition
IP65 so definitely safe near water of tank
http://www.qvsdirect.com/Metal-Halide-Floodlight-400W-with-ignitor-pr-18395.html

there are multiple options like this


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## scottturnbull (29 Dec 2008)

The LEDs on the Easy Life Paradiso seem to be there for aesthetic purposes. If you look at the brochure, the LEDs produce some amazing, deep-water style effects. It looks impressive, but so is the cost. When you add the price of the controller and lamps, it comes in around Â£1000.

As for Halides, I think the T5s are meant to extend the photoperiod. The Arcadia Series 4 comes with 2 x 150W Halides. I've used a 250W HPS lamp for growing lettuces and herbs. It covered an area 2m x 2m, and had to be suspended high above the plants to prevent burning. HPS and Metal Halides are very similar. With an aquarium, you would probably use the T5s from morning till noon, and from afternoon till evening, saving the Halides for a short noon-day burst. 

I haven't tried Halides with an aquarium, but I once tried growing aquatic plants in a container under HPS lamps, and managed to grow long, flowing tendrils of green hair algae. But that was using a 16hour photoperiod. 

To summarise: the Paradiso looks impressive, but the expense seems mainly due to its programmability, and the aesthetics it produces. The LEDs are concentrated in the middle. 
  My instincts tell me - rightly or wrongly - that T5s are included with Halides because 150-300W of light might be too much to use all day long. But that'll probably depend on the size of the tank.


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## Mark Evans (29 Dec 2008)

thanks guys. all the info i need. i'll have to mull over it all and digest some of the above information.


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