The truth about dimmable ballasts....

[Schwoop]

I can vouch for Solis-Tek dimmables, I run 50 of them and I dim them down depending on what stage were in, All running 1k lamps.

 

[Aerojoe]

I don't believe all questions have been answered, atleast not adequately. According to this study done on dimmable ballast/lights the spectrum does shift when dimmed, it shifts upwards slightly in kelvin temperature. Check out the study on pdf. I'm wondering if it shifts more significantly when you dim from 1000 down to 400, I've always wanted a solis tek for that reason, my lumateks only dim down to 600.

 

[TylerDurden119]

good read. so it appears dimming DOES have an effect on spectrum. seems like its marginal in HPS but quite significant on MH. as well as the dimming percentage and if the bulb is coated. I don't see anyone dimming down to 30% however a 1k is dimmable to a 400 which is a 60% decrease and goes over the 50% threshold for drastic change. so thats some good info right there, don't dim a 1k to 400 (which i have done, and noticed a hum on one of my bulbs which caused me to switch it immediately back to the 600 level but only that one bulb, which i felt was due to the somethin with that bulb as oppose to the dimming system). thanks for the contribution!!!

 

[Aerojoe]

good read. so it appears dimming DOES have an effect on spectrum. seems like its marginal in HPS but quite significant on MH. as well as the dimming percentage and if the bulb is coated. I don't see anyone dimming down to 30% however a 1k is dimmable to a 400 which is a 60% decrease and goes over the 50% threshold for drastic change. so thats some good info right there, don't dim a 1k to 400 (which i have done, and noticed a hum on one of my bulbs which caused me to switch it immediately back to the 600 level but only that one bulb, which i felt was due to the somethin with that bulb as oppose to the dimming system). thanks for the contribution!!!

hey tyler, thanks for stopping by. So you think that dimming down to 400 shifts the spectrum too much? I've been wanting a galaxy/solistek so I could possibly veg under 400 watts b4 I flipped, does that seem like a bad idea? what ballast are you using atm? what bulb/ballast were you using when you dimmed and it was humming? have you grown w/ 400 watt dimmed different bulbs w/ decent results?

 

[TylerDurden119]

personally i don't think so. i re read that article (not as high lol) and i see two major things. 1 a MH dimmed will increase its CCT temp(by 1500K) so it will go more to the blue spectrum of light, while a dimmed HPS' color spectrum will decrease by 50-200K, so more towards the yellow spectrum. I also seen that MH fluctuations are greater on all levels where HPS seems to jus be effected on temp(color), with a minor effect on CRI (which i just read up on and doesn't seem as important as the CCT impact). KILLER info in that piece, it also states that lumen depreciation isn't effected by dimming which is another rumor/myth i couldn't prove or disprove.

For the application your wanting to use it in seems like its perfect tool for the joby, if your just gona use a 1k hps bulb. personally i have 2 dual 6 lumateks and the 1k solis teks. i've dimmed both to their lowest setting for experimental sake and seen no issues other than that one bulb that had a periodic hum. its a generic bulb in the 1k solis tek. i still running em and everything kosher. from what i've read it doesn't seem like going over that 50% threshold applies to the HPS bulbs, as per the research. and TBH this article is fairly old, digital ballasts could and should have improved since then and some of these issues might have been addressed to the point where there isn't any spectrum change?

i think you got a good plan and the way i'd look at it, is if there's any growth reduction as a result of dimming, give'm an extra day of veg lol.

also if you have multiple lamps that are dimmable in one room, i've read of people alternately dimming the lamps with it having no adverse effects. i was gona try this out once i established a baseline with the strains im running.

really appreciate the article!!!

 

[ridegixxers]

please forgive me if im wrong but i read somewhere (i think from a instruction manual from a digital ballast company) that you have to "fire"/start your ballast at full power (for a 1k bulb) 1st. before you dim it down to, lets say 600watt.

is it me or does anyone else have a problem w/ this? im looking to upgrade (from a 400watt mag. ballast w/ a CMH bulb to a digital ballast w/ ultra sun's dual arc 1k bulb), but im having 2nd thoughts being that i have to be there to dim it down to 600watt.

is this true or can i just leave it at 600watt and will it "fire" correctly?

 

[pRiMo303]

please forgive me if im wrong but i read somewhere (i think from a instruction manual from a digital ballast company) that you have to "fire"/start your ballast at full power (for a 1k bulb) 1st. before you dim it down to, lets say 600watt.

is it me or does anyone else have a problem w/ this? im looking to upgrade (from a 400watt mag. ballast w/ a CMH bulb to a digital ballast w/ ultra sun's dual arc 1k bulb), but im having 2nd thoughts being that i have to be there to dim it down to 600watt.

is this true or can i just leave it at 600watt and will it "fire" correctly?

On my last grow I vegged w my 1000w Quantum dialed down to 50% and then bumped up to 75% at the beginning of flower and then 100%. No problems, and I definitely wasnt in there to dial it down manually after it struck. If it matters..Quantum ballast, Daystar & Magnum hoods, and Hortilux Mh/HPS bulbs.

 

[ttystikk]

KILLER info in that piece, it also states that lumen depreciation isn't effected by dimming which is another rumor/myth i couldn't prove or disprove.

really appreciate the article!!!

Lumen depreciation isn't affected by dimming, if anything it would last longer. Here's where things get interesting, though; dimming won't shorten the lifespan of the bulb, but running it a dimmed settings makes it act like it's already worn out! I say that because the prime factor in the rated lifespan of an HID bulb is lumen depreciation, or producing less lumens per watt than when it was new. People get a little nuts about this and change their bulbs a lot just to avoid it- and these same people are dimming their ballasts, not knowing that they are killing the efficiency (that is, lumens per watt) of their bulb's output even more than if it was just old! This is why I don't run my digi ballasts at dimmed settings.

I don't see how one could say that a digi ballast would/should be able to prevent spectrum shift when that's a function of the physical characteristics of the bulb?

I second that on the quality article- good stuff!

 

[ttystikk]

Hey, I gotta print a correction to the post above. After re-reading the article Aerojoe posted, it turns out that running an HID, most especially a metal halide bulb on a dimmed setting, DOES result in both lumen depreciation and shortened lifespan, sometimes drastically. Run your MH at 50% and they say you can expect it to load up with that blackish crud inside very quickly, and shorten the life of the bulb by up to 90%. Who knew?

The article doesn't discuss what happens if you overdrive the bulb by 10% though, I'd be interested to see those results.

Bottom line is that HPS is pretty clearly the most stable and robust of all the HID family, lasting longer, tolerating extended dimming well, showing more initial lumens per watt efficiency and less lumen depreciation over time than any of the others. Good stuff.

 

[ttystikk]

good read. so it appears dimming DOES have an effect on spectrum. seems like its marginal in HPS but quite significant on MH. as well as the dimming percentage and if the bulb is coated. I don't see anyone dimming down to 30% however a 1k is dimmable to a 400 which is a 60% decrease and goes over the 50% threshold for drastic change. so thats some good info right there, don't dim a 1k to 400 (which i have done, and noticed a hum on one of my bulbs which caused me to switch it immediately back to the 600 level but only that one bulb, which i felt was due to the somethin with that bulb as oppose to the dimming system). thanks for the contribution!!!

If you read the article and tables (figure 2) closely, you'll find that because the bulb's lumens per watt efficiency drops along with wattage, it puts out less than half its rated lumens even when still driven at 60%. So you don't need to dial down so far, the bulb has more or less already crossed your 50% threshold for you. The bad news? You're still spending 60% of the power, and running bulbs at such low power settings does accelerate their demise. In fact, after reading that article closely, I would advise against anyone running an MH bulb at any dimmed setting at all, something about how the mix of gases in the envelope can't take it. HPS is much more stable and less prone to depreciation, but it still will if run at very low power settings for extended periods.

 

[fishwhistle]

I emailed solis tek twice to get their take on this but apparently their ballasts are way better than their customer service,Lol.By the way i received an auto response both times saying they would get right back to me but never heard a thing,almost as if they did not want the liability of answering these particular questions.

 

[TylerDurden119]

If you read the article and tables (figure 2) closely, you'll find that because the bulb's lumens per watt efficiency drops along with wattage, it puts out less than half its rated lumens even when still driven at 60%. So you don't need to dial down so far, the bulb has more or less already crossed your 50% threshold for you. The bad news? You're still spending 60% of the power, and running bulbs at such low power settings does accelerate their demise. In fact, after reading that article closely, I would advise against anyone running an MH bulb at any dimmed setting at all, something about how the mix of gases in the envelope can't take it. HPS is much more stable and less prone to depreciation, but it still will if run at very low power settings for extended periods.

yea i missed that the first go round. second time not so high i found it lol

thanks for puttin that out there. it really only applies to the mh bulbs

I emailed solis tek twice to get their take on this but apparently their ballasts are way better than their customer service,Lol.By the way i received an auto response both times saying they would get right back to me but never heard a thing,almost as if they did not want the liability of answering these particular questions.

interestingggg and not confidence inspiring. however the proof is in the pudding, n so far so good. what i do have confidence in is all the stuff we figured out n that puts me at ease.

 

[fishwhistle]

Right on tyler the proof IS in the pudding and alot of folks including god w/50 ballasts running cant be wrong,just strange that they cant answer that question but they are right on top of others.

 

[StickiestAbyss]

Yes you can 1000w bulb on the 600w setting for vegging without harming the bulb. This is actually what the dimmable function was designed for. On the super lumen setting the watt output will be around 1050 watts. The Lumatek dimmable ballast is dimmable not by percentage of overall output, but by increments i.e., 1000w, 750w, and 600w. You can run a 1000w bulb on any of these settings, but you might get a different spectrum if you run a 1000w bulb on a 750w or 600w setting, but the difference in spectrum usually isn't drastic.

 

[tedsprogz]

um, ohm's law covers both ac and dc. not sure where you came up with that

OHM'S law only applies for DC voltage. Resistance in DC is static. In AC it is called Impedance and is dynamic based on frequency. Ohms law is Amps=Volts/Resistance, not Amps=Volts/Impedance. While ohms law is true for DC and AC it is impossible to factor in resistance in AC since it changes depending on frequency. And for the color change, that color difference would be seen when comparing a 600 to a 1000 every time. If you dim a 1000 to a 600, the minute color change would be the same if you replaced the 1000 with a 600. I have 2 Lumatek 1000w dimmables and both show a decrease of 7Nm when going from 1000 to 600. When i switch it with a 600W Lumatek digital on full blast its still 7Nm off the 1000 Watt. so while the 600 does show a slight drop, this is not due to the dimming. If i get around to grabbing a 400W lumatek, i'll test the 600 dimmed to a 400 and see the drop compared to a 400 at full blast.(note when i say decrease, Im taking about the location of the peak.)

 

[slap14]

Been trying to decide on a new ballast Solis tek or Quantum. Here is an email I got back from Solis Tek yesterday, by the way they responded a couple times in less than 3 hours.

"thanks for your email. our 1000 Watt ballast can dim a 1000watt bulb to 600 and 400. however, the intended color spectrum the bulb was designed to output will not be reached since your not running it at 100%
likewise you can put a 600w lamp in the 1000w ballast but make sure the setting is on 600w.
I hope this helps. if you have any other questions or concerns please email or call! thanks"

Hope this helps other people. They did say if you run a 600 watt bulb on the 600 watt setting instead of dimming a 1000 watt bulb the spectrum is fine

Slap

 

[Nobodynobody]

I read some where on a magazine. Run your lamp at its wattage. If there is supper lux from the digi, thats good too.

 

[ttystikk]

Engineers get paid a lot of money to design equipment, and they work hard to ensure that it will work to optimal effect when operated within its design specifications. It's what they do. The design specification for a 1000w bulb is... 1000 watts. What I don't get is, if it's obvious you wouldn't put diesel fuel in your gas powered mower, then why the fuck would you want to run your 1000 watt bulbs at 600? Either raise the damned thing- 40% higher gives better results than dropping the voltage, since there's no bulb degradation or spectrum shift- or get the proper bulb and ballast for the job. Do you use a wrench to hammer nails? If so, then you're not working on my jobsite! It's called properly matching the equipment to the task requirements. As a grower, that's YOUR job, and your responsibility.

How is this Solis Tek's, or any other ballast mfrs' problem? For that matter, how is this somehow a 'defect' in the bulbs? The answer is, it's not- it's simple misuse by the consumer who doesn't bother to educate themselves, and then wants to pass blame for their ignorance off onto someone else.

 

[ttystikk]

1.yes raising light is better..someyimes yah gotta dial it down due to too high heat
dialed down to 50% gives 25% of the oomph of 100% 1kw

my take:it was fun to be able to dial down for new transplants or the odd hot day ..but
losing all the oomph while only losing 50% of the electricity made me feel like NOT doing it again..75% is better but in the end i'd just turn afew 1k's off and maybe rotate them in a heat wave.
but in the end 1kw is better hahaha

If you're dimming the bulb to cut heat, then I would say you're operating without enough of a safety margin in your cooling strategy. Inexpensive solutions include a swamp cooler or perhaps running the flower room at night when it isn't so hot.

 

[ttystikk]

ttys,

yes , yes and YES...my cooling strategy is air from outside...it gets too hot...it does nay work

split flower room...swamp cooler..sounds good..not enough room...low ceiling , tall shrubbery..
maybe i can fit one in.

So you have two flower rooms on a flip? That's excellent- so now we only need to worry about keeping the day side cool. A swamp cooler, possibly in two stages, might be enough. Place one swamper in line with your outside air intake (outside the growroom, I'm guessing still inside the house, right?), and then place another one inside the growroom itself. As the day warms up, relative humidity automatically falls- so the swamp cooler will inexpensively reverse that process.

Hope this helps, or at least gives you some ideas. Clearly, you're doing something right- that plant is fuckin' Rockin'!