Does anyone use 1000w DE (Non ducted) lamps with 8 foot ceilings? I'm curious about dimming ballasts.

Right now I have just finished framing in walls for my veg and flower. I'm about to start getting into electrical work and can't decide on 1000w or 750w lamps. The price between the two units is negligible so that isn't a factor. I'm having trouble finding concrete info on the downsides to dimming your lamps. If there isn't really any downside to dimming the ballast I'd rather go with 1000w lights. My grow style may change. Maybe I decide to go to SOG somewhere down the line and have all this extra head space I'd be happy I had the stronger lights. So if a light is adjustable from 600w-1150w why would I buy 750w lamps? Thanks for any advice!

I’ve ran 1000w with a ceiling under 7 feet. Just gotta keep control of your plant size.

You ever think about using cool tubes? I have ran 1000’s dimmed down to 750, but never for a grow start to finish. I can’t see it being an issue tho. With 8 foot ceilings, unless your running raised NFT systems or ebb and flow where you lose head room, you should be able to rock 1000’s

even with the above mentioned systems, If plants are kept smaller, you should be ok.

You can get away with 1000w air-cooled hoods with 8' ceilings, 1000w DE Gavitas are going to be a bit more difficult. By the time you factor in the light, distance from canopy and pots you are left with like 3' of canopy space which isn't much.

Bulbs are designed to be ran at their intended wattage to produce the efficiency and spectrum they were made for. Check this out.

Thundercat said:

I’ve ran 1000w with a ceiling under 7 feet. Just gotta keep control of your plant size.

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Yes exactly that. Thanks for the input! The way I learned to grow and have been for the last 4 years doesn't give me the ability to get my plant height down low enough for the recommended bulb to canopy distance. Now I could throw this all to the wind and try to grow a completely new way but I want to get a couple good harvests with the method I know before I start tweaking things.

Doing more research, and I very well may be wrong here, but it seems adjustable ballasts are mainly adjustable for using different bulbs. Yes dimming may be useful for certain times when temperatures spike, but the feature is mostly there to use different bulbs. This is an interesting graph.



So you lose a lot of efficiency by lowering the wattage. Looking at a 1000w gavita fixture for instance you have adjustments as follows: 600/660/750/825/1000/1150 You can always dim the 1000 bulb to any of those settings or boost it at 1150. You can put in a 750 bulb and boost it to 825 or dim it to 600 or 660. But you're going to blow bulbs start fires etc if you try to boost that 750 bulb past 825.

So unless I'm missing something very obvious here, and please let me know if I am, it would be smartest for me to buy the 1000w fixture and use 750 bulbs with the ballast adjusted to 750 or 825. Then I have the option down the line to throw in 1000 bulbs and adjust accordingly. Is this thinking correct? Thanks!

NukaKola said:

You can get away with 1000w air-cooled hoods with 8' ceilings, 1000w DE Gavitas are going to be a bit more difficult. By the time you factor in the light, distance from canopy and pots you are left with like 3' of canopy space which isn't much.

Bulbs are designed to be ran at their intended wattage to produce the efficiency and spectrum they were made for. Check this out.

https://gavita.com/retail/app/uploads/Light-Matters-7-GCM-US16-3.pdf

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Oh man thanks NukaKola! The graph I found elsewhere looks like it was pulled directly from there. At first glance it seems to confirm what I was thinking. I'm going to dive into it now thanks again!

I’m not sure where you are located, but my ballasts are 1000 watt digital dimmable ballasts. You don’t change the bulb. It is always the 1000. You just turn a knob and dim the 1000 to 75% or 50%

calvert60@ said:

You ever think about using cool tubes? I have ran 1000’s dimmed down to 750, but never for a grow start to finish. I can’t see it being an issue tho. With 8 foot ceilings, unless your running raised NFT systems or ebb and flow where you lose head room, you should be able to rock 1000’s

even with the above mentioned systems, If plants are kept smaller, you should be ok.

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By cool tubes do you mean DE fixtures that are air cooled? I have only briefly looked into them but after growing for so many years with single ended ducted hoods I'm sick of the clutter and fans and cleaning.

My grow has 8’ ceilings. Air cooled, the table is probably a foot off the floor and the pots are 2 gal. Maybe 10” high. I manage this no problem.

I guess you have a few options.
You change your grow method.
buy a light smaller than the 1000
Run a 1000 dimmed.
Run air cooled hoods.

sorry I can’t be more help.

calvert60@ said:

I’m not sure where you are located, but my ballasts are 1000 watt digital dimmable ballasts. You don’t change the bulb. It is always the 1000. You just turn a knob and dim the 1000 to 75% or 50%

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I'm located in the states. That's interesting. There's only a couple brands that I use and am very familiar with but have definitely seen a few more than that. I've never seen them adjustable by percentage.

I get you don't change the bulbs as you adjust/dim your ballast, but what I'm reading and understanding is you absolutely can. A 600w ballast will run a 600w bulb as intended. A 1000w digital ballast dialed to 600w will run a 600w bulb as intended. You don't ideally change bulbs often but if you found a great deal on 1000w digital ballasts with a setting for 600w and you ran your room with 600w bulbs there should be no difference running that vs 600w ballasts.

With mine, you have to use a 1000 watt bulb. You are able to change from a 1000hps to 1000mh. You can never run a smaller bulb (600) you can only dim the 1000

Cheaper ballasts dim 50%/75%, more expensive ballasts dim to 400w/600w.

Personally, I wouldn't run DE's with 8' ceilings. I'd stick with either Air-cooled 600w/1000w SE HPS, CMH, or LED. They do make air-cooled DE hoods but they are like $350/ea.

CMH's or Bar style LED's are great for SOG.

calvert60@ said:

My grow has 8’ ceilings. Air cooled, the table is probably a foot off the floor and the pots are 2 gal. Maybe 10” high. I manage this no problem. View attachment 4698464

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Looking great!



My current setup is similar in terms of lighting. This picture is about 10 months old the trellis setup is different now. Have higher ceilings and could redo the room but it's producing well so guess it stays as is there. I'm sick of lowering and raising lights and ducting and cleaning hoods. Plus I want to try something new. Ideally I would just move my current setup to the new location and use the room with higher ceilings for the DE fixtures but it sounds nice to start fresh.

My new spot a couple days ago. Poured and leveled the floor last week. Inside framing is finished now. Flower on right veg is in front from this view. 100 Amp service is in.

If price isn’t a factor, I have always been told the 600s are most efficient.

I do the same, lower my lights and ratchet them up. But I have always questioned, do we really need to? You look at the big producers, usually their lights are stationary. Why? Because there is 300 of them in the room? Lol do their yields suffer from this I wonder?

your room looks amazing. I feel like your questioning everything tho. Lights, set up, the whole works.

NukaKola said:

Cheaper ballasts dim 50%/75%, more expensive ballasts dim to 400w/600w.

Personally, I wouldn't run DE's with 8' ceilings. I'd stick with either Air-cooled 600w/1000w SE HPS, CMH, or LED. They do make air-cooled DE hoods but they are like $350/ea.

CMH's or Bar style LED's are great for SOG.

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Interesting I usually buy whatever is cheapest at the store for ballasts since they all seem to last the same and never seen one with less than 2 year warranty so if they die just trade them back for a new one.

I've never had luck with CMH in flower. Never tried the bar style LED's but used a couple black dogs for a couple rounds in the flower room. They were fucking spendy over a grand if I remember right. They sucked and are now just in the veg room. Kind of turned me off to LED but those Gavita 1700E fixtures look like they would change my mind. I just can't bring myself to kit out a 12 fixture room with them because of my previous experience with LED and the cost obviously doesn't help. Crap I have it in my head I'm going DE and I don't think I'm going to be able to get off it. I don't think I can convince myself to go with any ducted lighting.

calvert60@ said:

If price isn’t a factor, I have always been told the 600s are most efficient.

I do the same, lower my lights and ratchet them up. But I have always questioned, do we really need to? You look at the big producers, usually their lights are stationary. Why? Because there is 300 of them in the room? Lol do their yields suffer from this I wonder?

your room looks amazing. I feel like your questioning everything tho. Lights, set up, the whole works.

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Thanks calvert! Haha yeah I've always been told with single ended bulbs you're lighting the plants where with the big grows (DE stationary lights) you're lighting the room. Guess that's the easiest way people explain it to me. I'd say with single ended bulbs and hoods yeah we definitely need to ratchet away. I like to get as close as possible without burning the plants.

Bigger grows though even not 300 just, hmm let me find a picture of a friends room. His lights are stationary and so far away, though this is before they were triggered. Still he pulls more grams per watt than me (so don't think yields are suffering) and it's just so much easier to maintain and work in.




"I feel like your questioning everything tho. Lights, set up, the whole works." I definitely got a bit off topic but mostly curious about my original topic. I should have clarified in the post that I meant 1000w DE not ducted.

Hmmm I haven’t tried them, but now you have me thinking. If you do run them, let me know how it goes!!

Depending on the ballast you can run both De and E40, I've got a de parabolic and vertical parabolic, I've got the option of using regular 400w, 600w and 1000w De bulbs +10% boost.
Through the 4 seasons and various plant stages the flexibility is priceless.

I have DE's in a basement grow and I do alright with it.