dual arc bulbs?

[blue-dreamer]

Are dual arc bulbs better than HPS bulbs? 1000watters?

 

[hiboy]

Cant tell u that yet, im runnin 3 ushio dual arcs along with 4 hps lamps
The dual arcs are a trip, you can see a mini yellow and mini blue glow in the lamp, blue by the base and yellow by the tip
trippy
h

 

[blue-dreamer]

so ur running 7000watts of light? How do u run that much without worrying about electric company?

 

[hiboy]

so ur running 7000watts of light? How do u run that much without worrying about electric company?

blue
warehouses use alot of power for machinery, etc.
plus only on 12 hrs
havent had any issues to date.
h

 

[treehugger]

The big problem with dual-arc bulbs is that the mh portion ages much faster than the hps element. At the price they charge for these, you'd be much better off just pairing up individual bulbs and retiring them as they pass peak output.

 

[hiboy]

The big problem with dual-arc bulbs is that the mh portion ages much faster than the hps element. At the price they charge for these, you'd be much better off just pairing up individual bulbs and retiring them as they pass peak output.

tree,

how did u figure this out,
is there something u can link to explain that or do you believe that mh lamps go out sooner than hps
h

 

[Tobor the 8th Man]

These lamps don't make perfect sense to me. The theory of mixed spectrums certainly has merit. However, the combination of 600w and 400w in the same bulb is flawed. I think they just did this because it was the only combo that would work in one of the standard size ballasts. Those being 250w, 400w, 600w and 1000w. It is the only wattage combination that adds up to one of those standard ballast sizes. 600 + 400= 1000

If you had a 600w lamp and a 400w lamp over the same plants you wouldn't have them mounted at the same height over the plants. The 600w would be higher than the 400w because it has a longer distance of penetration. Same with these combo bulbs. The 600w side would have to have better penetration than the 400w side.

Now that they have adjustable ballasts they should make one with different dimmer wattage points. A 1000w could have a 800w setting and now a 400w HPS can be combined with a 400w MH. A 600w could have a 500w setting for a 250w HPS and 250w MH combo. At least that would make sense.

I would rather have a 1000w HPS and just add supplemental 400w MH lighting if I wanted the mix spectrum. Why make your 1000w bulb have the penetration of a 600w on one end and the penetration of a 400w on the other end?

 

[Tobor the 8th Man]

You could have a switch box that the ballast output goes to and have it set to turn on a 1000w HPS one day and a 1000w MH the next day and mix the spectrums while maintaining 1000w penetration.

 

[ttystikk]

Good points, Tobor. The reason the 400W MH filament is in a dual arc bulb is because that's the source for the shorter blue end spectrum light. This light tends to be more intense per unit of output and has better penetration than the red end of the spectrum, which is what the HPS is for. That's why they design these bulbs 600HPS/400MH as opposed to other combos.

that intense blue-shifted spectrum is why MH bulbs don't get the lumen rating HPS does; the rating doesn't take into account the power of blue spectrum light ralative to red weighted HPS.

As far as the assertion that MH deteriorates faster than HPS, that's not really true; most manufacturers will have you swap out your MH bulb sooner because they know veg. lights stay on for longer than flowering bulbs, so they're just making that suggestion based on counting total hours of burn time.

I've used dual element bulbs and they work fine. Not super awesome, but if you only have a small space or limited funds and need a light that does everything, it's a good choice. Another time it's useful is the last couple weeks of bloom, when you want plenty of light but want some UV and shorter wavelength light to help the girls finish frosty.

 

[m1rage]

Side by sides have been done-look for threads by jackmayoffer, or look through posts by Jalisco kid, pretty sure they both offer good reviews. Jack said it definitely improved density, trichromes, etc.. One complaint I have heard is that the way the bulb is oriented makes it so that the light from the MH and HPS is distributed poorly and not evenly. Just a thought. I just picked up 4 Hort SuperHPS's, gonna get some dual arcs for my next room but couldn't shell out the extra to try them out at the moment...

 

[hiboy]

Not sure if i would run them dual arcs alone, i have them staggered ,, hps, dual,hps and so on for a total of 7k. I think it will be interesting to watch.
h

 

[MissyGreen]

I thought I read some threads that said the dual-arcs have problems with digital ballasts. Is this still true?

 

[daddygreen]

I did a run with straight hortilux dual arc and the a straight run with hps this is what i came up wit there very crystaly but the yield wasnt there when it went on the scale wit the dual arcs then wit the hps wasnt as crystly but i was happy at the end.......

 

[ttystikk]

I thought I read some threads that said the dual-arcs have problems with digital ballasts. Is this still true?

The problem is the ballast, not the bulb. ANSI S52 is the standard by which both bulbs and ballasts are to be in compliance with, and most digital ballasts don't meet this standard. Insane, I know, but true. Dual arcs have the reputation of being more prone to failure with non-conforming digital ballasts, but that's my own subjective experience, and not anything based on hard facts.

I did a run with straight hortilux dual arc and the a straight run with hps this is what i came up wit there very crystaly but the yield wasnt there when it went on the scale wit the dual arcs then wit the hps wasnt as crystly but i was happy at the end.......

Your experience is similar to what a lot of people have said. If you want to get closer to the best of both worlds, run the HPS through flower until the last couple weeks, then switch to dual arc to finish. That way, you get better yield and good resin production.

 

[calbunn]

tree,

how did u figure this out,
is there something u can link to explain that or do you believe that mh lamps go out sooner than hps
h

halides in general have a wave shift at 200 hours and are the fastest and steadiest in lumen depreciation of any of the HID lamps. From initial strike any MH will be @ 70% lumen output within 10,000 hrs. But along that 10,000 hours is a steady drop off in lumen output.

check it for yourself with a light meter as you measure day one levels then check those same levels every 1000 hours. On a 12/12 that means take the readings monthly to see what I mean. By 6 months on a 12/12 you've lost 20% of the lumen output.

If you're noticing a drop off in veg as the lamps age after 6 months use, the halides output can be why.

 

[daddygreen]

im doing that now ttystikk i running hps till the 6th week then finishing up with the dualarc to get the UV!!!!!!!!!!!

 

[ttystikk]

halides in general have a wave shift at 200 hours and are the fastest and steadiest in lumen depreciation of any of the HID lamps. From initial strike any MH will be @ 70% lumen output within 10,000 hrs. But along that 10,000 hours is a steady drop off in lumen output.

check it for yourself with a light meter as you measure day one levels then check those same levels every 1000 hours. On a 12/12 that means take the readings monthly to see what I mean. By 6 months on a 12/12 you've lost 20% of the lumen output.

If you're noticing a drop off in veg as the lamps age after 6 months use, the halides output can be why.

Where did you get your information? I'm all for factual data, just cite references for us skeptics... ;)

If true, it makes me wonder what the lumen depreciation numbers are for HPS, as well.

At 18 hours/ day of veg then, a full year is 6570 hours, roughly 2/3 of 10K hours. If lumen depreciation is linear (where would one go to find that information?) then one could guess 20% lumen depreciation in a year?

 

[calbunn]

Where did you get your information? I'm all for factual data, just cite references for us skeptics... ;)

If true, it makes me wonder what the lumen depreciation numbers are for HPS, as well.

At 18 hours/ day of veg then, a full year is 6570 hours, roughly 2/3 of 10K hours. If lumen depreciation is linear (where would one go to find that information?) then one could guess 20% lumen depreciation in a year?

I respect skepticism. In fact it wasn't until I performed the 1000 hour test for myself that I noticed that the drop off in umole count or lumen output, depending on your meter, was so rapid.

As to MH wavelength shifts; ANSI has a designated method which they measure acceptable chromaticities CCT of linear fluorescent lamps that keep them from wavelength deviations as defined within an accepted 4 step standard known as the MacAdam ellipse.

For your MH reference I cite the NLPIP, an independent testing lab, report; 'Color variations among MH lamps are particularly noticeable during the first 100 hours (h) of operation' in which 320 & 400 watt pulse and probe start MH lamps were tested and found the lamps CCT performance to be outside of the ANSI 4 step MacAdam ellipse in CCT shift

While the MacAdam ellipse does not strictly apply to MH lamps it's important for the grower to know that MH lamps don't meet that ANSI standard for testing because of their wavelength instability. As you'll see by this report @ 100 hours and at 40% lamp life testing the MH lamps Kelvin and CCT shifts have either risen or fallen to the point that final CCT shifts measure between -81 thru -772 depending on the MH lamp being tested.

For the grower seeking stable UV wavelengths throughout the grow and across generations this represents a challenge in uniformity as well as the rapid lumen depreciation and thermal contribution issues that must be overcome from a MH source.

This is a multi-page link;http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/mwmhl/characteristics5.asp#

Appendix Test Results; http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/mwmhl/appendix.asp

As to lumen depreciation of MH or HPS lamps there's a lumen depreciation schedule on the very bottom of one of these pages, just hit next, which compares a variety of lamp types that in my opinion is fairly weighted based on a wide sampling of mfg's published data.