Twin Arc metal halide bulbs

nigerbang

Active Member
Ran on up this and thought this was super intresting
Article by Jake Adams from Reef Builder
"The twin arc metal halide lamp from Advanced Lighting Solutions was one of the most exciting and innovative product unveiled at the Marine Aquarium Expo this past weekend. The twin arc lamps are about the length of a standard 400w mogul base metal halide lamp but they include two separate arc tubes within the lamp envelope. The arc tubes of the Twinarc do not fire simultaneously but instead, they are fired in alternation each time the lamp is turned on and off. We spent a good half hour turning this lamp on and off and we can tell you it is an amazing thing to see this lamp fire up the “other” arc tube again and again. Although a typical lamp would take 15 or more minutes to cool down and fire again, the off-duty arc tube only warms up a little bit by comparison and the Twinarc is ready to fire up again in a couple minutes. The Twinarc will be available only as a mogul base bulb in 250w and 400w sizes with a dual 20K flavor for extended lamp life and a 10K/20K combo which will alternate between intensity and color. How ALS can basically offer two bulbs for the price of one at $99 is beyond us but we are very excited to see the bulbs put to creative use. Advanced Lighting Solutions will be developing a special pendant to accomodate the spaced out lamp arcs to keep the arc tubes in the sweet spot of the reflector. The bulbs should be available in 6 weeks and they will be hitting the *Other sites* as soon as they are available. We’ll have the exclusive on the spectral graphs of the Twinarc in a couple weeks, follow the link for more pics of the amazing Twinarc lamp from ALS."
 

t316

Active Member
Is all of this happening inside of "one" bulb, or is the alternation taking place between multible bulbs within a setup?
 

nigerbang

Active Member
The basic premise of it with a 10k/20k bulb is that during the day your coral gets the 10k light needed to speed growth but the timer cuts of and back on and instead of firing the 10k tube with will jump to the 20k for the blue look that people like..
 

t316

Active Member
$99...I assume it probably has the about the same life span as normal bulbs (replace once a yr)
 

nigerbang

Active Member
Originally Posted by T316
http:///forum/post/3042139
$99...I assume it probably has the about the same life span as normal bulbs (replace once a yr)

unless you get one of the 10k/10k or 20/20.. It would last around 18-24 months since it is only firing one at a time..
 

scsinet

Active Member
Originally Posted by T316
http:///forum/post/3042139
$99...I assume it probably has the about the same life span as normal bulbs (replace once a yr)

It would depend on the duty cycles of each tube. The tube that spends more time on per day would dictate the effective life of the lamp.
For example, if an old school halide lamp runs for 10 hours per day, for 365 days, then that means a halide lamp lasts for about 3600 hours.
So if you run one lamp for 6 hours per day and one for 4, the 6 hour tube would be what dictates the life. 3600 hours / 6 hours = 600 days.
 

t316

Active Member
Makes sense SCSI, making it well worth the investment. But if one of the two tubes goes out then the whole thing is no good (for the normal time cycle). This scenario is probably no more likely than a traditional bulb though.
 

scsinet

Active Member
Well here is the thing...
This sort of design depends on the idea that a hot tube will not ignite. So what they do is they put a smaller resistor on the igniter of the tube they want to fire first (when energizing a totally cold lamp). Then when power is rapidly cycled, the hot tube won't ignite, causing voltage to rise enough to cross the threshold the other tube's igniter and fire it.
The problem is that when one arc tube dies completely, it won't ignite to heat up. If the affected tube happens to be the one set up by the manufacturer to be the "first" tube, then the entire lamp is dead. If it's the "second" tube, you'd be okay.
I'd expect that to really maximize your investment, you'd want to run a 50/50 cycle. This would effectively create a lamp with double the life as each arc tube is only running 1/2 the time.
A couple other thoughts... first... I wonder how the rapid power cycling affects the lifespan of the hot arc tube. It's not considered good practice to try to re-ignite a hot halide lamp because it can shorten it's life. I wonder what this daily hot restart will do to the lifespan of the first arc tube?
Also, it occurs to me that this sort of lamp would not work in a pulse start system. Pulse start ballasts ignite the lamp differently, so I would expect that on pulse start systems, it would be a craps shoot as to which arc tube strikes first...
 

king_neptune

Active Member
Ok so let me get this straight...you get 10k during the day,then 20k at night? This means bright intense light during daylight, then a lower blue glow in the evening hours, and finally shutting off completely when I go to sleep.
Considering I do 8/8/8 (the final being completely off), I am jumping my MH consumption to 16hours a day, instead of the 8 I originally planned.
My power company will love that.
What are the benefits to 20k? do I get special coral growth? Or is it simply an excuse to have a pretty blue glow over my tank in the evening?
I was thinking on my new reef system doing mixed bulbs.
IE. 10k/20k/10k on my 250wx3 hood.
 

nigerbang

Active Member
You get 10k X ammount of hours for better growth then when the timer clicks it switches to a 20k. Doesnt run both at the same time so it would only be pulling the same ammount as a normal SE bulb with the exception of the quick spike from firing the bulb.. Still only 8 hours..
20k looks miles better than 10's for the most part but 10's have a better growth rate..
Say for example.. 8 hours.. hell.. Noon to 8pm... you get home from work at five.. 10k from noon until say 4:54 then it turns off and as the 10k is cooling down the 20 fires.. from 4:59-8pm.. Still only 8 hours...
 

king_neptune

Active Member
ok, now i get it. thnx fer the find.
one other question:
what If i did 10/20/10 or 20/10/20 on my triple ballast hood?
would the blue tint be noticeable in either case?
or would having a 10k over power it?
 

scsinet

Active Member
Originally Posted by King_Neptune
http:///forum/post/3113460
ok, now i get it. thnx fer the find.
one other question:
what If i did 10/20/10 or 20/10/20 on my triple ballast hood?
would the blue tint be noticeable in either case?
or would having a 10k over power it?
Keep in mind that in a twin-arc lamp, one arc tube will ignite first on a cold lamp, every time. Which one is built into the lamp.
So unless they make separate 20/10 and 10/20 lamps, you can't do what you are trying to do.
 

lancepender

New Member
So, if I buy three 400w's, and have them set up on a 8 hr run time. per day. is it safe to say, once each bulb is turned on to the same k spectrum as the other two bulbs. Each day I can have 10k running for 8 hrs then turn off. Then the next day have the 20k running for 8 hrs then turn off. Then the 10k's running for 8hrs then turn off the next day, and so on???
If this is how this bulbs work.. I have another question.. How does this bulb know witch ark was used before?? If each ark is cold..
I would think by only using one ark at a time per day. We would get double the useful time.. Witch is very good..
 

scsinet

Active Member
Originally Posted by lancepender
http:///forum/post/3119634
If this is how this bulbs work.. I have another question.. How does this bulb know witch ark was used before?? If each ark is cold..
It doesn't. The whole idea of these lamps is that a "changeover" from one arc tube to the other is triggered when a hot lamp is kicked off and back on immediately. The second arc tube will only ignite if the lamp is hot-restarted.
So one spectrum per day is not an option.
The idea behind this is that 10K produces horrid looking light to most, but the best growth. 20K is just the opposite. The idea is that the 10K runs while you are away at work, etc, and it kicks over to the 20K for viewing time, later in the day.
I don't know what these lamps cost, but I'm betting it's nearly or more than twice a regular lamp, so I don't know why someone wouldn't just run two sets of lamps instead... then they could do whatever timing they wanted.
 

nigerbang

Active Member
Originally Posted by SCSInet
http:///forum/post/3119838
I don't know what these lamps cost, but I'm betting it's nearly or more than twice a regular lamp, so I don't know why someone wouldn't just run two sets of lamps instead... then they could do whatever timing they wanted.
As far as I have heard from alot of people that are "in the know" that they are going to run about $85-$100 each.. Not really that bad.. Considering that those new Phoenix SE are $100 each and Radiums are around $80 a bulb..
 

scsinet

Active Member
I guess that makes me a bit suspicious. Apart from the arc tube, a halide lamp is a few wires and a bit of glass. There is no special manufacturing process or otherwise involved.
Also, halide lamps run the gamut in pricing, with construction being basically identical.
That wou'd lead me to believe that the arc tube is the most expensive part, since the R&D and manufacturing processes involved make the most difference in terms of PAR and color rendition.
So if a double arc tube lamp costs only slightly more than a single, how good are these tubes?
 
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