# Xenon HID, good or bad?



## madhatter4 (Dec 13, 2007)

So Ive been doing lots of research about the difference between the Xenon HID's for automotive headlights and the normal metal halide HID's used for reef and plant growing. From everything I can find they are both metal halide but the Xenon HID's use Xenon gas instead of Argon to give usable light during warm up. The use of Xenon gas also helps fill in the low spots of a normal metal halide spectrum. The only down side I can see is the short life span of ~3000 hours. About a years worth. I may be able to increase this with some fans for cooling but I don't know.

The reason I am interested in the Xenon HID's is because they are low wattage (35 watts) and I want to keep my tank (90 gallon, 22" high) low light but also get some depth penetration. I want HID's due to the point source effect/shimmer effect mainly, but depth penetration is a bonus. Also, normal 50 watt metal halide would probably work fine for what I want but I can get two Xenon HID's bulb and ballast from ebay for $40 shipped (Xenon HID conversion kit). It would be a LOT cheaper then a normal metal halide setup.

I have pretty much made up my mind to DIY some Xenon HID's 8000K into my hood with a DIY aluminum flashing refector. $40 for the lights and ballast, $10 for the flashing, and I have plenty of wood and a PC power supply for the HID's 12 volt ballast. 

If it doesn't work I wont be out much money but I wanted to see if anyone here has a good reason for me to NOT use Xenon HID's. I have searched many forums and found little info on this subject. There may be a valid reason why not to, but I have yet to find it.

Opinions please,

Thanks


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## ryanlogic (Dec 21, 2009)

*im interested*

im interested to see what kind of results you get.

some people on nano-reef.com have mentioned it in the past, ad i am certain that several people advised against it. but if you could get a decent spectrum for plant growth it may be a cost effective way to light smaller planted aquariums. Or to add supplemental light to certain areas in a larger tank.


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## madhatter4 (Dec 13, 2007)

I got my Xenon HID's in the other day. $39 shipped from ebay, 35 watt, 8000K.

Some background:

My tank is a 90 Gallon reef ready; 48"L x 18"D x 22"H(sand to surface). My old lights(as of the other night) were two 36" T12 bulbs 6500K, 30 watt overdriven 2X each. There were from my 29 Gallon which is now my sump. This is how it looked, minus the hood.










I bought some aluminum flashing to make a reflector for the HID's but I didn't like it so I decided to cannibalize the old fixture for its reflector, much better. A little DIYing and I came up with two of these. The coke can is for scale.











My camera is a cheap point and click so the pictures do not really convey what the lights looks like, but they give a good idea.

Just the two 35 watt 8000K Xenon HID's. Very nice color. White with some blue and I love the shimmer affect but not good for coverage. Looks dimmer in person.










After my initial testing with the HID's I doubt they alone will give me sufficient light intensity to grow much so I decided to upgrade my old 36" T12's 6500K with two 48" T8's 6500K 32 watt, still 2X overdriven each. The T8's do not have reflectors yet but at least they light up the far ends of the tank. I am going to order two IceCap T5 SL reflectors for them. I think that will help the light intensity a bit. Here are just the T8's, no reflector.











The pictures make the brightness look about the same as the HID's but in person the HID's seem a bit dimmer. The HID's are definitely more white/blue. The T8's (6500K) are really yellow in comparison. Individually the HID's and T8's don't really work well but when I combined them, I really liked the effect. Good coverage, great color, and I still get the shimmer affect. The tank is much brighter running both the HID's and the T8's and has a more crisp feel about it.











All in all I'm happy with the end result. The HID's were cheap and really made a difference in the appearance of my tank. I don't know if they alone could grow plants but I don't see why not. They might be perfect for a smaller tank like a 29 Gallon. When they burn out I may upgrade to the 50/55 watt Xenon HID's, about $10 more.

Anyone care to take a guess as what my light level will be once I get the reflectors on my T8's? I want to stay in the low light area with no CO2. My current plants are Hornwort, Java Moss, Java Fern, and some other low light plants I got in a lump package.


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## ZID ZULANDER (Apr 15, 2008)

What did you use as a power source for the HID's?


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## madhatter4 (Dec 13, 2007)

I'm using a computer power supply. The one in this picture is 300 watt PS I hacked up a few years ago to use as a bench top power supply. It has banana plugs for 3.3V, 5V, 12V, and an adjustable 1.26 - 22V. I added a voltmeter to is as well. The 12V rails can handle 12 Amps, more then enough for the HID's.










Here is a how to if anyone is interested.

http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply


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## xmas_one (Feb 5, 2010)

You could probably score some nice reflectors in the junkyard.


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## madhatter4 (Dec 13, 2007)

I thought about that but the bulb would have to be vertically orientated to be of any use. I don't know if it matters for these HID's but I know it does for other metal halides. I may still look into it.


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## ryanlogic (Dec 21, 2009)

like the anchor


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## jwm5 (May 9, 2010)

my guess is you would run in to issues in the long run, HID kits from ebay are most likely for use to retrofit into vehicles. At least with the one pictured, the wiring would be exposed to a lot of heat being inside the reflector like that. Compared to a car where the wire only touches the back of the bulb and the heat is insulated by the reflector and air from the car moving. Also I know that cheaper HID kits usually have cheaper ballasts that can burn out quick. I am all for DIY and I like the idea of this for HID, but again, heat could be an issue, of you could figure out a way to isolate the wiring from the bulb I think it would be better long term. you could look at a junkyard like someone above noted, that would at least give you a way to mount the HID bulb like if would be in a car. Maybe look for a truck of something with larger headlight lens/reflectors, otherwise the beam would be too focused, lighting an aquarium 24" deep vs lighting the road 30+ feet ahead of you...


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