1000w and Co2

[SensiBlaze]

Hey guys I got a quick Q
I'm running a 1000w hps over a 5x5x8 area with a 480cfm exhaust and a passive intake from a window. I have the light 20" from my canopy and temps hang around 77-82F lights on.

I'm wondering if I am wasting electricity on light that my plant can't use without supplemented Co2. I have read that cannabis can't utilize all 1000w without it. I have also been told as long as the temps are in check the yeild will be much higher.. So lots of conflicting information lol.. What do you guys think? Should I dim to 750w to save electricity or can I indeed yield higher with 1000w and just passive intake from outside?

 

[SPLFreak808]

I've done a few 1000w SE grows in a 5x4x7 cab, i used a sealed sun system hood and would regularly hit ambient temps of 85f.

My main issue was keeping the plants from finishing close to the bulb, with 7ft (4ft free) of height it was very easy to run out of vertical room for me.

i ran shorts blue dream scrogged and it finished like a champ in that cab without a single hiccup under 1000w.

I've also ran tahoe OG scrogged in that same cab and it finished 10" away from the glass, turned the top colas to shit (my fault lol,leggy ass strain)

50w/ft2 isn't much of an issue, its the height of the 1000w bulb and the genetics.

 

[SensiBlaze]

Thanks for the reply! I was having mad issues with heat when I first installed my 1000w hortilux.. Luckily I was able to get an intake going from outside (temps are beautiful in Colorado this time of year) which keeps me around 80F.. This grow I've also been tying the plants down every time they grow an inch which is giving me tons of extra height to work with! With this method my Durban Poison has only gotten 3" taller 2 weeks into flower.

So another question I have.. With my new vent setup I can get my light 8" away when dimmed to 750w. When it's full blast I can have it around 18" away. Am I feeding my plants more with 750w at 8" or 1k at 18"? It's a hortilux super hps if that makes any difference. Been trying to figure this one out for a long time but can't find a damn thing on that subject lol

 

[SPLFreak808]

Thanks for the reply! I was having mad issues with heat when I first installed my 1000w hortilux.. Luckily I was able to get an intake going from outside (temps are beautiful in Colorado this time of year) which keeps me around 80F.. This grow I've also been tying the plants down every time they grow an inch which is giving me tons of extra height to work with! With this method my Durban Poison has only gotten 3" taller 2 weeks into flower.

So another question I have.. With my new vent setup I can get my light 8" away when dimmed to 750w. When it's full blast I can have it around 18" away. Am I feeding my plants more with 750w at 8" or 1k at 18"? It's a hortilux super hps if that makes any difference. Been trying to figure this one out for a long time but can't find a damn thing on that subject lol

I did it the same way, pulled from a window and spit it out another window.
I also had to use lights at night because of my tropic location,I had to stop all that though because smell became a crazy issue.

Honestly your gonna have to try it, i cant say what the outcome will be but i can say 8" is a bit close even dimmed to 750. Personally i wouldn't let colas get any closer than 20" from the bulb at 1kw, maybe 15" at 750w.

Imo, Keep tying them down. Better safe than sorry

 

[SensiBlaze]

Now that you mention it I think you're right lol.. I didn't even think about bleaching issues since this is my first grow bigger than 600w.. But definitely, experimentation is the best way to learn!
Really appreciate your input man

 

[Gquebed]

The question youre asking is....

"If i can yield say 1lb dimming my light down to 750 and yield say 1.25 lbs at 1000...is it worth it?"

The answer is subjective. It depends on what you think its worth? For a fast and loose example.... If it costs you say 200 bux for the electricity to grow that 1 lb at 750w and say 225 to grow 1.25 lbs att 1000w... is it worth it to you?

 

[kermit2692]

My experiences.. Dimming your light isn't something i suggest. Your ballast will continue to use the same level of power consumption regardless of the Dimming rendering the comment above mine largely negated ..(did they fix this engineering issue? News to me if they have) also your spectrum will be altered due to Dimming and your ballast will have to disperse the extra energy and can run hot, probably not good for it... So anyway it is likely very inefficient to do that and you won't benefit by getting the light any closer than 18-24 inches. you aren't fully taking into account the relationship of heat/light/closeness/humidity. They all play together so getting your light down to eight inches away while also being at 750 watts and still keeping the temp down under eighty leaves you two issues, light bleaching (which i have gotten to happen before when i was waiting for a shipment in the mail and let plants get too tall before flip) and then the other issue is you're creating a very dry area right at your canopy. The drier your plant is in general, the more reactive it will be to temperature issues. These are some of the answers to reasons why people don't seem to understand the difference between a plant in 100 degrees outside versus inside. My advice is keep your light on the highest setting and back it up until you can keep the temp under eighty at the canopy if without co2. Can go a bit hotter with co2. Have to consider this, if you're running hot, no amount of extra light will do literally any good at all. I promise you in a dry environment like Colorado running constantly over eighty will destroy your crop. Will look great until you chop it then quickly show it's true quality!! Your weak link is not light at this point so you should hang it where it's a safe distance away not only heat wise but also considering intensity, leave it be, and focus your energy on other parameters.

 

[kermit2692]

Btw are you only running that wattage over one plant?! Lol.... You are so much more than covered if so. You would be fine under a 400 even THEN you can get it down to 12-18 inches from canopy.. Going to be moving up to foco area from Midwest soon enough always happy to give some pointers and burn one. Man do i miss the Chiba hut!

 

[Gquebed]

My experiences.. Dimming your light isn't something i suggest. Your ballast will continue to use the same level of power consumption regardless of the Dimming rendering the comment above mine largely negated ..(did they fix this engineering issue? News to me if they have) also your spectrum will be altered due to Dimming and your ballast will have to disperse the extra energy and can run hot, probably not good for it... So anyway it is likely very inefficient to do that and you won't benefit by getting the light any closer than 18-24 inches. you aren't fully taking into account the relationship of heat/light/closeness/humidity. They all play together so getting your light down to eight inches away while also being at 750 watts and still keeping the temp down under eighty leaves you two issues, light bleaching (which i have gotten to happen before when i was waiting for a shipment in the mail and let plants get too tall before flip) and then the other issue is you're creating a very dry area right at your canopy. The drier your plant is in general, the more reactive it will be to temperature issues. These are some of the answers to reasons why people don't seem to understand the difference between a plant in 100 degrees outside versus inside. My advice is keep your light on the highest setting and back it up until you can keep the temp under eighty at the canopy if without co2. Can go a bit hotter with co2. Have to consider this, if you're running hot, no amount of extra light will do literally any good at all. I promise you in a dry environment like Colorado running constantly over eighty will destroy your crop. Will look great until you chop it then quickly show it's true quality!! Your weak link is not light at this point so you should hang it where it's a safe distance away not only heat wise but also considering intensity, leave it be, and focus your energy on other parameters.

Ill beg to differ on your opinion on dimming. I used to use 2x 1000w dimmable ballasts and always started at 600w during veg then turned up to 1000w towards the end of veg, to prepare for bloom. The corresponding electricity usage went up by 25%...which i measured by tracking my meter daily.

I was curious. And being the only one in the house....all variables were the same...

 

[SPLFreak808]

My god that would be one crazy ballast if it used resistors on the output line lol

 

[kermit2692]

Ill beg to differ on your opinion on dimming. I used to use 2x 1000w dimmable ballasts and always started at 600w during veg then turned up to 1000w towards the end of veg, to prepare for bloom. The corresponding electricity usage went up by 25%...which i measured by tracking my meter daily.

I was curious. And being the only one in the house....all variables were the same...

Ok. So you are trying to say then that your house only uses approx two 1000w lights worth of power on an average month??? Because if dimming your light half way saved you 25 percent on your bill that would mean your light is approx. half of your bill every month....lol one of us is too high for math right now idk who yet lol... Either that or I'm jealous at how little power you manage to use

 

[kermit2692]

Eh may have been just a rumor or maybe they did fix it... I'm talking ten fifteen years back that it was common to hear that's how they work...i am going to laser temp my ballast dimmed and full power to check for heat dispersion variance to be sure because i swear it's warmer dimmed.... HOWEVER the other reasons not to do it are for sure hundred percent correct. You will lose bulb life, change your spectrum, and likely lose on Yield....also i understand if a ballast worked that way it would get hot kind of figured that's why the shell is made as a giant heat sink pull the excess heat away.

 

[kermit2692]

I used to be one of the eighteen year old shit talking know it all kids on here.. Now I'm turning into the old head that doesn't know his shit anymore because i can't keep up with the times..ughhhhh nooooooo lol..

"back in my day my ballast had one power setting..ON!"

 

[SPLFreak808]

I used to be one of the eighteen year old shit talking know it all kids on here.. Now I'm turning into the old head that doesn't know his shit anymore because i can't keep up with the times..ughhhhh nooooooo lol..

"back in my day my ballast had one power setting..ON!"

Lol its all good, its just part of keeping up with technology.

Newer ballast are modulated on the output, they have a circuit (pwm) that controls the frequency/pulse of the output line resulting in only drawing what it needs. If a ballast had to dissipate 250w through a resistor it will get hot to the touch.

When you dim, instead of dumping the load as heat it just lowers the millisecond of each strike, resulting in less wattage arriving at the bulb.

 

[Gquebed]

Ok. So you are trying to say then that your house only uses approx two 1000w lights worth of power on an average month??? Because if dimming your light half way saved you 25 percent on your bill that would mean your light is approx. half of your bill every month....lol one of us is too high for math right now idk who yet lol... Either that or I'm jealous at how little power you manage to use

Your logic is flawed. I meant to say exactly what I said.

 

[deno]

One plant can easily fill 4'x4' if you scrog and you know what you're doing, so 1kw is not overkill. Just don't start flowering until you have sufficient size.

 

[Mullumbimby]

One plant can easily fill 4'x4' if you scrog and you know what you're doing, so 1kw is not overkill. Just don't start flowering until you have sufficient size.

The OP's talking 5x5, so 25sq ft. That's 40watts /sq ft, which is the important measure.
I can't imagine how long it would take to veg a single plant up to 25sq ft but it's a long time to veg for sure.

 

[kingtitan]

I use a 5x8x6.5 tent but only use 5x5 space for grow, the other part is equipment and veggies/flowers. I use 1k hortilux on my cannabis and my lights are usually 18-22" inches. IF i cap out with the air cooled hood I LST a bit more aggressively or super crop before week 3 flower is done. Don't DIM your bulb especially if you fork over extra money for premium bulbs like hortilux so you don't mess up the tuned spectrum. If electric costs are worth it then go for it knowing that you will have less yield and potency. Electric here is dirt cheap and my setup costs 25 bucks a month during flower (4 cents per Kwh)

 

[Gquebed]

Thanks for the reply! I was having mad issues with heat when I first installed my 1000w hortilux.. Luckily I was able to get an intake going from outside (temps are beautiful in Colorado this time of year) which keeps me around 80F.. This grow I've also been tying the plants down every time they grow an inch which is giving me tons of extra height to work with! With this method my Durban Poison has only gotten 3" taller 2 weeks into flower.

So another question I have.. With my new vent setup I can get my light 8" away when dimmed to 750w. When it's full blast I can have it around 18" away. Am I feeding my plants more with 750w at 8" or 1k at 18"? It's a hortilux super hps if that makes any difference. Been trying to figure this one out for a long time but can't find a damn thing on that subject lol

Theres a luman chart tha corresponds to light wattage and distance in Jorge Cervantes grow book. I'm sure it's pictured online somewhere too...

 

[SensiBlaze]

Thanks a bunch to everyone who has dropped some knowledge in this thread! I've decided to stick with 1kw @ 18" away. Temps are a very steady 76-78 all during lights on I'm getting some seriously fat branches on my girls now that I've gotten the heat and lights dialed in. My limiting factor now I think is humidity, which never drops below 75% lights on lol. Not running into any issues besides still getting a feel for my strains.. But I'm pulling my smallest plant of 6 in a few days so will update with weight soon. Really hoping for at least a pound all together. Each plant was vegged for 6 weeks under the 1kw and flowered at 15"..They're completely covering about 30sq ft of space